scholarly journals Model Based Indirect Conicity Estimation Technique for Solid Axle Railway Wheelset

2021 ◽  
Vol 40 (4) ◽  
pp. 753-760
Author(s):  
Erum Saba ◽  
Imtiaz Hussain Kalwer ◽  
Mukhtiar Ali Unar
Keyword(s):  
Simulation Model ◽  
Dynamic Behavior ◽  
Frictional Contact ◽  
Ride Comfort ◽  
Research Work ◽  
Railway Vehicle ◽  
Estimation Technique ◽  
Model Based ◽  
Simulation Results ◽  
Linearized Model

Conicity is an important characteristic that helps the railway vehicle to steer itself down the track. However during the operation, the conicity tends to change inconsistently due to frictional contact at the wheel-rail interface. Safety, reliability and ride comfort which are utmost importance for journey are adversely affected due to the changes in conicity level beyond certain limit. Several techniques have been employed for monitoring the health of the railway wheelset however still a significant potential exists to investigate the wheelset conicity. This paper presents a model based technique to monitor the wheelset condition which contributes to the wheel flats due to decrease in conicity level and the problem of false flanges due to increased level of conicity. In this paper an unconstrained solid axle railway wheelset is considered for study. The dynamic behavior of the wheelset is analyzed at different conicity levels to understand the effect of the conicity on the wheelset. In order to demonstrate the potential of this research work a simulation model is developed in Matlab/ Simulink to mimic the behavior of an actual wheelset. Simplified linearized model of the wheelset is used to estimate the dynamics of the wheelset. From the simulation results it is evident that the frequency of vibration is changing with the changes in conicity level. In this way using the proposed method the conicity level is indirectly identified. The results produced by simulation model are satisfactory.

A COMPARISON OF SIMULTANEOUS KELLY BETTING STRATEGIES

2013 ◽  
Vol 6 (2) ◽  
pp. 1-28
Author(s):  
Andrew Grant ◽  
Peter W Buchen
Keyword(s):  
Simulation Model ◽  
Dirichlet Distribution ◽  
Relative Performance ◽  
Portfolio Optimisation ◽  
Model Based ◽  
Premier League ◽  
Simulation Results ◽  
English Premier League

In this paper we consider the problem of Kelly betting on simultaneous games, and the relative performance of betting strategies that use multibets compared to those that do not. We develop a simulation model based on the Dirichlet distribution to test the performance of three Kelly betting strategies using the empirical odds distribution from the 2007-08 English Premier League Season. This model allows us to control for the size of a bettor’s edge and the noise of this edge. The simulation results suggest that the Kelly using multibets of all levels outperforms the portfolio optimisation approach of betting on single game outcomes only. We also provide a discussion regarding the practicalities of implementing the strategies.

Vehicle Attitude Control Simulation Based on Soft and Hard Damping

2012 ◽  
Vol 263-266 ◽  
pp. 660-663
Author(s):  
Yu Zhuo Men ◽  
Haibo Yu ◽  
Xin Pan
Keyword(s):  
Simulation Model ◽  
Attitude Control ◽  
Control Algorithm ◽  
Shock Absorber ◽  
Model Based ◽  
Control Simulation ◽  
Damping Characteristics ◽  
Simulation Based ◽  
Simulation Results ◽  
The Impact

In order to study the impact of vehicle attitude changes on stability, vehicle attitude control simulation model based on soft and hard damping characteristics was built. The model was applied to simulate vehicle straight driving and turning driving, thus simulating various vehicle attitudes in driving. The simulation results show that this model was correct and the control algorithm was feasible; the damping impact on a variety of vehicle attitudes in the driving process can be simulated in advance by adjusting the damping; and the changes of soft and hard damping adjustable shock absorber damping can effectively change the vehicle riding comfort and handling stability.

scholarly journals Signal Based Indirect Wheel Profile Estimation Technique for Solid Axle Railway Wheelset

2021 ◽  
Vol 40 (2) ◽  
pp. 443-449
Author(s):  
Khurram Shaikh ◽  
Imtiaz Hussain Kalwer ◽  
Khakoo Mal ◽  
Bhawani Shanker Chowdhry
Keyword(s):  
Fourier Transform ◽  
Frictional Contact ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Direct Impact ◽  
Estimation Technique ◽  
Lateral Dynamics ◽  
Wheel Profile ◽  
Profile Estimation ◽  
The Relationship

Wheel profile is a very important factor that helps the steering performance of the railway vehicle. However, during the operation, the wheel profile tends to vary inconsistently due to frictional contact at wheel-rail interface. This paper focuses on the problem of railway wheelset profile and its alteration that affects the performance of railway vehicle. Signal-based indirect estimation technique using Fast Fourier Transform (FFT) is proposed to establish a relationship between dynamic response of vehicle and wheel profile. It is observed that changes in wheel profile has direct impact on the frequency of lateral dynamics. The effect of vehicle speed is also analyzed on the yaw and lateral motions of the wheelset. The effectiveness of the proposed technique in determining the relationship between the frequency of the oscillation and conicity level of the solid axle railway wheelset is demonstrated by developing simulation model in MATLAB and Simulink.

Simulation Model of the Dynamic Behavior of a Tire Running Over an Obstacle

1988 ◽  
Vol 16 (2) ◽  
pp. 62-77 ◽  
Author(s):  
P. Bandel ◽  
C. Monguzzi
Keyword(s):  
Simulation Model ◽  
Dynamic Behavior ◽  
Black Box ◽  
Box Model ◽  
Vehicle Suspension ◽  
Empirical Relationships ◽  
Static Tests ◽  
High Speeds ◽  
Dynamic Forces ◽  
Vehicle Suspension System

Abstract A “black box” model is described for simulating the dynamic forces transmitted to the vehicle hub by a tire running over an obstacle at high speeds. The tire is reduced to a damped one-degree-of-freedom oscillating system. The five parameters required can be obtained from a test at a given speed. The model input is composed of a series of empirical relationships between the obstacle dimensions and the displacement of the oscillating system. These relationships can be derived from a small number of static tests or by means of static models of the tire itself. The model can constitute the first part of a broader model for description of the tire and vehicle suspension system, as well as indicating the influence of tire parameters on dynamic behavior at low and medium frequencies (0–150 Hz).

QoS aware Multi-Path Routing using Link Scheduling Algorithm

2019 ◽  
Vol 09 ◽  
Author(s):  
Satyasrikanth Palle ◽  
Shivashankar
Keyword(s):  
Cellular Networks ◽  
Scheduling Algorithm ◽  
Research Work ◽  
Scheduling Algorithms ◽  
Turnaround Time ◽  
Link Scheduling ◽  
Spatial Reuse ◽  
Mobile Cellular ◽  
Simulation Results ◽  
End To End

Objective: The demand for Cellular based multimedia services is growing day by day, in order to fulfill such demand the present day cellular networks needs to be upgraded to support excessive capacity calls along with high data accessibility. Analysis of traffic and huge network size could become very challenging issue for the network operators for scheduling the available bandwidth between different users. In the proposed work a novel QoS Aware Multi Path scheduling algorithm for smooth CAC in wireless mobile networks. The performance of the proposed algorithm is assessed and compared with existing scheduling algorithms. The simulation results show that the proposed algorithm outperforms existing CAC algorithms in terms of throughput and delay. The CAC algorithm with scheduling increases end-to-end throughput and decreases end-to-end delay. Methods: The key idea to implement the proposed research work is to adopt spatial reuse concept of wireless sensor networks to mobile cellular networks. Spatial reusability enhances channel reuse when the node pairs are far away and distant. When Src and node b are communicating with each other, the other nodes in the discovered path should be idle without utilizing the channel. Instead the other nodes are able to communicate parallelly the end-to-end throughput can be improved with acceptable delay. Incorporating link scheduling algorithms to this key concept further enhances the end-to-end throughput with in the turnaround time. So, in this research work we have applied spatial reuse concept along with link scheduling algorithm to enhance end-to-end throughput with in turnaround time. The proposed algorithm not only ensures that a connection gets the required bandwidth at each mobile node on its way by scheduling required slots to meet the QoS requirements. By considering the bandwidth requirement of the mobile connections, the CAC module at the BS not only considers the bandwidth requirement but also conforming the constrains of system dealy and jitter are met. Result: To verify the feasibility and effectiveness of our proposed work, with respect to scheduling the simulation results clearly shows the throughput improvement with Call Admission Control. The number of dropped calls is significantly less and successful calls are more with CAC. The percentage of dropped calls is reduced by 9 % and successful calls are improved by 91%. The simulation is also conducted on time constraint and ratio of dropped calls are shown. The total time taken to forward the packets and the ration of dropped calls is less when compared to non CAC. On a whole the CAC with scheduling algorithms out performs existing scheduling algorithms. Conclusion: In this research work we have proposed a novel QoS aware scheduling algorithm that provides QoS in Wireless Cellular Networks using Call Admission Control (CAC). The simulation results show that the end-to-end throughput has been increased by 91% when CAC is used. The proposed algorithm is also compared with existing link scheduling algorithms. The results reveal that CAC with scheduling algorithm can be used in Mobile Cellular Networks in order to reduce packet drop ratio. The algorithm is also used to send the packets within acceptable delay.

Research on On-Line Anti-Icing Technology for Carenary along Electrified Railway

2013 ◽  
Vol 676 ◽  
pp. 321-324
Author(s):  
Lei Guo ◽  
Qun Zhan Li
Keyword(s):  
Simulation Model ◽  
Heat Balance ◽  
Normal Operation ◽  
Balance Equations ◽  
Model Based ◽  
Static Var Generator ◽  
On Line ◽  
Electrified Railway ◽  
The Heat Balance

Accidents of icing on catenary have great impacts on normal operation of trains. An on-line anti-icing technology used static var generator (SVG) for catenary was proposed, which can prevent icing formation without interrupting trains normal operation. The heat balance equations for catenary were solved, whose results were compared with data provided by TB/T 3111 and testing show the equation was correct. The simulation model based on Matlab was bulit , whose results and analysis show the correctness of the method.

scholarly journals Macro Modeling of V-Shaped Electro-Thermal MEMS Actuator with Human Error Factor

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 622
Author(s):  
Dongpeng Zhang ◽  
Anjiang Cai ◽  
Yulong Zhao ◽  
Tengjiang Hu
Keyword(s):  
Neural Network ◽  
Simulation Model ◽  
Bp Neural Network ◽  
Human Error ◽  
Calculation Model ◽  
Fuzzy Mathematics ◽  
Ansys Simulation ◽  
Macro Modeling ◽  
Error Factor ◽  
Simulation Results

The V-shaped electro-thermal MEMS actuator model, with the human error factor taken into account, is presented in this paper through the cascading ANSYS simulation model and the Fuzzy mathematics calculation model. The Fuzzy mathematics calculation model introduces the human error factor into the MEMS actuator model by using the BP neural network, which effectively reduces the error between ANSYS simulation results and experimental results to less than 1%. Meanwhile, the V-shaped electro-thermal MEMS actuator model, with the human error factor included, will become more accurate as the database of the V-shaped electro-thermal actuator model grows.

Comprehensive Analysis for Influence of Controllable Damper Time Delay on Semi-Active Suspension Control Strategies

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Yechen Qin ◽  
Feng Zhao ◽  
Zhenfeng Wang ◽  
Liang Gu ◽  
Mingming Dong
Keyword(s):  
Time Delay ◽  
Dynamic Characteristics ◽  
Ride Comfort ◽  
Hybrid Control ◽  
Sliding Mode ◽  
Control Strategies ◽  
Active Suspension ◽  
Test System ◽  
Suspension Control ◽  
Simulation Results

This paper presents a comprehensive comparison and analysis for the effect of time delay on the five most representative semi-active suspension control strategies, and refers to four unsolved problems related to semi-active suspension performance and delay mechanism that existed. Dynamic characteristics of a commercially available continuous damping control (CDC) damper were first studied, and a material test system (MTS) load frame was used to depict the velocity-force map for a CDC damper. Both inverse and boundary models were developed to determine dynamic characteristics of the damper. In addition, in order for an improper damper delay of the form t+τ to be corrected, a delay mechanism of controllable damper was discussed in detail. Numerical simulation for five control strategies, i.e., modified skyhook control SC, hybrid control (HC), COC, model reference sliding mode control (MRSMC), and integrated error neuro control (IENC), with three different time delays: 5 ms, 10 ms, and 15 ms was performed. Simulation results displayed that by changing control weights/variables, performance of all five control strategies varied from being ride comfort oriented to being road handling oriented. Furthermore, increase in delay time resulted in deterioration of both ride comfort and road handling. Specifically, ride comfort was affected more than road handling. The answers to all four questions were finally provided according to simulation results.

Effect of unsupported sleepers on dynamic behavior of running vehicles and ride comfort index

2021 ◽  
pp. 095440622198937
Author(s):  
Mojtaba Azizi ◽  
Majid Shahravi ◽  
Jabbar-Ali Zakeri
Keyword(s):  
Numerical Model ◽  
Dynamic Behavior ◽  
Multibody Dynamics ◽  
Field Test ◽  
Ride Comfort ◽  
Vehicle Speed ◽  
Comfort Index ◽  
Railway Industry ◽  
Flexible Track ◽  
Train Speed

Nowadays, with various advancements in the railway industry and increasing speed of trains, the design of railway tracks and vehicles has become vitally important. One of the frequent problems of ballasted tracks is the existence of unsupported sleepers. This phenomenon occurs due to the lack of ballast underneath the sleepers. Here, a model is presented, in which a flexible track model in a multibody dynamics program is developed, in order to study the dynamic behavior of a vehicle. By utilizing the model, it is feasible to simulate unsupported sleepers on the flexible track including rail, sleeper, and ballast components. In order to verify the results of numerical model, a field test is performed. Findings indicate that, in the case of a single unsupported sleeper through the track, the ride comfort index increased by 100% after increasing the train speed from 30 to 110 km/h. Moreover, when it is needed to have ride comfort index improvement over the uncomfortable level, the vehicle speed should be less than 70 km/h and 50 km/h for tracks with one unsupported sleeper and two unsupported sleepers, respectively.

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