scholarly journals Assessment of Active Wheelset Steering System Using Computer Simulations and Roller Rig Tests

2021 ◽  
Vol 11 (24) ◽  
pp. 11727
Author(s):  
Jan Kalivoda ◽  
Petr Bauer ◽  
Zdeněk Novák
Keyword(s):  
Computer Simulations ◽  
Signal Transmission ◽  
Field Tests ◽  
Steering System ◽  
Lateral Acceleration ◽  
Railway Vehicle ◽  
Wireless Signal ◽  
Curvature Estimation ◽  
Roller Rig ◽  
Curved Track

The paper is created within a project which aims to design a system of active wheelset steering for an electric four-axle locomotive. The wheelset steering system enables reduction in forces acting in the wheel-rail contacts in a curved track and consequently a reduction in wear and maintenance costs of both vehicles and rails is achieved. The project consists of three main parts: computer simulations, scaled roller rig experiments, and field tests. The paper is focused on the fundamental aspects of the first and the second part on the project. Track curvature estimation based on the rotation of the bogies towards the car body is proposed and assessed by computer simulations across varying track radiuses, vehicle speeds, and friction conditions. The scaled roller rig has been innovated in order to simulate bogie run in a curved track with uncompensated value of lateral acceleration and instrumented with a system of measurement of lateral wheel-rail forces. The experimental bogie has been equipped with systems of active wheelset steering and measurement of axle-box forces. The experiment setup, newly developed and applied systems of forces measurement and wireless signal transmission, and results of the first experiments are described in detail. Performed computer simulations and scaled roller rig experiments show that active wheelset steering is effective and practically implementable method of reducing guiding forces acting between railway vehicle wheels and rails in a curved track.

On the Planning and Construction of Railway Curved Track

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Sono Bhardawaj ◽  
Rakesh Chandmal Sharma ◽  
Sunil Kumar Sharma ◽  
Neeraj Sharma
Keyword(s):  
High Speed ◽  
Time Derivative ◽  
Railway Track ◽  
Lateral Acceleration ◽  
Transition Curve ◽  
Railway Vehicle ◽  
Geometric Conditions ◽  
Curve Track ◽  
Curved Track ◽  
Transition Curves

Increasing demand for railway vehicle speed has pushed the railway track designers to develop high-quality track. An important measure of track quality is the character of the transition curve track connecting different intersecting straight tracks. A good transition curve track must be able to negotiate the intermittent stresses and dynamic effects caused by changes in lateral acceleration at high speed. This paper presents the constructional methods for planning transition curves considering the dynamics of movement. These methods consider the non-compensated lateral acceleration, deviation in lateral acceleration and its higher time derivatives. This paper discusses the laying methods of circular, vertical and transition curves. Key aspects in laying a curved track e.g. widening of gauge on curves are discussed in this paper. This paper also suggests a transition curve which is effective not only from a dynamic point of view considering lateral acceleration and its higher time derivative but also consider the geometric conditions along with the required deflection angle.

Research on robust adaptive sliding film fault-tolerant control under nonlinear distortion of signal transmission in amorphous flat air-to-ground wireless ad-hoc network system

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zhifang Wang ◽  
Jianguo Yu ◽  
Shangjing Lin
Keyword(s):  
Nonlinear Distortion ◽  
Ad Hoc ◽  
Fault Tolerant ◽  
Signal Transmission ◽  
Network System ◽  
Long Distance ◽  
Content Type ◽  
Wireless Signal ◽  
Robust Adaptive ◽  
Self Organizing

Purpose To solve the above problems and ensure the stability of the ad hoc network node topology in the process of wireless signal transmission, this paper aims to design a robust adaptive sliding film fault-tolerant controller under the nonlinear distortion of signal transmission in an amorphous flat air-to-ground wireless ad hoc network system. Design/methodology/approach This paper designs a robust adaptive sliding film fault-tolerant controller under the nonlinear distortion of signal transmission in an amorphous flat air-to-ground wireless ad hoc network system. Findings The simulation results show that the amorphous flat wireless self-organizing network system has good nonlinear distortion fault-tolerant correction ability under the feedback control of the designed controller, and the system has the asymptotically stable convergence ability; the test results show: the node topology of the self-organizing network structural stability is significantly improved, which provides a foundation for the subsequent realization of long-distance transmission of ad hoc network nodes. Research limitations/implications Because of the chosen research approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed propositions further. Originality/value The controller can extract the fault information caused by nonlinear distortion in the wireless signal transmission process, and at the same time, its feedback matrix K can gradually converge the generated wireless signal error to zero, to realize the stable transmission of the wireless signal.

scholarly journals Research on Bogie Frame Lateral Instability of High-Speed Railway Vehicle

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Chen Wang ◽  
Shihui Luo ◽  
Ziqiang Xu ◽  
Chang Gao ◽  
Weihua Ma
Keyword(s):  
High Speed ◽  
Dynamics Simulation ◽  
Lateral Acceleration ◽  
Railway Vehicle ◽  
Lateral Instability ◽  
Bogie Frame ◽  
High Speed Railway ◽  
Long Time ◽  
Line Test ◽  
Equivalent Conicity

In order to find out the reason for the bogie frame instability alarm in the high-speed railway vehicle, the influence of wheel tread profile of the unstable vehicle was investigated. By means of wheel-rail contact analysis and dynamics simulation, the effect of tread wear on the bogie frame lateral stability was studied. The result indicates that the concave wear of tread is gradually aggravated with the increase of operation mileage; meanwhile the wheel-rail equivalent conicity also increases. For the rail which has not been grinded for a long time, the wear of gauge corner and wide-worn zone is relatively severe; the matching equivalent conicity is 0.31-0.4 between the worn rail and the concave-worn-tread wheel set. The equivalent conicity between the grinded rail and the concave-worn tread is below 0.25; the equivalent conicities are always below 0.1 between the reprofiled wheel set and various rails. The result of the line test indicates that the lateral acceleration of bogie frame corresponding to the worn wheel-rail can reach 8.5m/s2, and the acceleration after the grinding is reduced below 4.5m/s2. By dynamics simulation, it turns out that the unreasonable wheel-rail matching relationship is the major cause of the bogie frame lateral alarm. With the tread-concave wear being aggravated, the equivalent conicity of wheel-rail matching constantly increases, which leads to the bogie frame lateral instability and then the frame instability alarm.

Study on the Larger Bus Body Stability of Bend Steering

2014 ◽  
Vol 494-495 ◽  
pp. 3-7
Author(s):  
Jie Jin ◽  
Fu Ming Qin ◽  
Wei Zhou ◽  
Wen Liang Li
Keyword(s):  
Road Construction ◽  
Steering System ◽  
Lateral Acceleration ◽  
Bend Radius ◽  
Technical Improvement ◽  
Power Train ◽  
Vehicle Modeling ◽  
Stability Performance ◽  
Bus Body ◽  
Turning Radius

When a larger bus steering in the corners, it easily affected by the lateral acceleration so that the vehicle sideslips or rolls over, using the research methods of combining with real vehicle modeling and simulation to ensure the safety and comfort of the passengers. Analyzed and researched systems that affecting vehicles stability performance, including power train, steering system, brake system and the vehicles road model of the system curve .On this basis, compared to the acceleration values which the motorbus body can withstand in different states, proposing the acceleration values when human feel comfortable, uncomfortable and terrible, then conducted simulation tests under different turning radius and speeds. The results showed that: on the premise of ensuring the safety and comfort of vehicle passengers, the allowable speed limit with different bend radius is not the same; then it drew series of limit speeds allowed by series of bend radius, providing a reference and basis for future road construction and motorbus technical improvement.

scholarly journals Experimental Study on the Vibration Control Effect of Long Elastic Sleeper Track in Subways

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaopei Cai ◽  
Dacheng Li ◽  
Yanrong Zhang ◽  
Qian Miao ◽  
Rixin Cui
Keyword(s):  
Vibration Reduction ◽  
Field Tests ◽  
Urban Rail Transit ◽  
Control Effect ◽  
Tunnel Wall ◽  
Vibration Effect ◽  
Urban Rail ◽  
Vertical Displacements ◽  
Curved Track ◽  
Reduction Effect

The vibration effect of urban rail transit has gained attention from both academia and the industry sector. Long Elastic Sleeper Track (LEST) is a new structure for vibration reduction which has recently been designed and applied to Chinese subways. However, little research has been devoted to its vibration reduction effect. In this study, field tests were conducted during peak transit hours on Beijing Subway Line 15 to examine the vibration reduction effects of the common ballastless track and LEST on both straight and curved sections. The results demonstrate that although LEST increases the wheel-rail vertical forces, rail vertical displacements, and rail accelerations to some extent, these effects do not threaten subway operational safety, and vibrations of track bed and tunnel wall are positively mitigated. LEST has an obvious vibration reduction effect at frequencies above 40 Hz. In straight track, the vibration of bottom of the tunnel wall measured in one-third octave bands is reduced by 10.52 dB, while the vibration at point on the tunnel wall at 1.5 m height is reduced by 9.60 dB. For the curved track, the vibrations at those two points are reduced by 9.35 dB and 8.44 dB, respectively. This indicates that LEST reduces vibrations slightly more for the straight track than for the curved track.

Accelerometer Sensor Based Fall Sensing for Elderly

2015 ◽  
Vol 73 (1) ◽  
Author(s):  
Anas Mohd Noor ◽  
Hafizudin Zainudin ◽  
Normaheran Hanafi ◽  
Siti Aishah Baharuddin ◽  
Mohamad Aliff Abdul Rahim
Keyword(s):  
Mobile Communications ◽  
Signal Transmission ◽  
Cost Effective ◽  
Fall Detection ◽  
Detection Algorithm ◽  
Prototype System ◽  
Accelerometer Sensor ◽  
Wireless Signal ◽  
Overall Performance ◽  
Key Parameter

Fall can be recognized as an abnormal or action of losing an upright motion which will cause people especially elderly to suffer from pain and more seriously can affect one’s health. Being able to detect fall is key parameter to decrease the risk of severe injury to the seniors. There are such existing fall detection products on the market to assist elderly so that immediate response could be taken. However, due to complexity system, high cost and employing outside technology, these products initiate limitations such as maintenance and system enhancement. In this project, a fall detection device and system is developed using local technology, simple and cost effective. The prototype system consist of accelerometer sensing circuit, microcontroller with wireless signal transmission, Global System for Mobile Communications (GSM) notification alert for mobile phone and graphical user interface (GUI) to obtain real-time monitoring. The simple fall detection algorithm is developed to ensure false detection could be minimized. The overall performance of the developed device and system is proven reliable and practical. 

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