scholarly journals Optimization of the design of relay valves for rail vehicles braking systems in the context of train traffic safety

2019 ◽  
Vol 294 ◽  
pp. 03013
Author(s):  
Sylwin Tomaszewski ◽  
Franciszek Tomaszewski ◽  
Włodzimierz Stawecki ◽  
Patryk Urbański ◽  
Mariusz Far ◽  
...  
Keyword(s):  
Traffic Safety ◽  
Low Temperatures ◽  
Control Method ◽  
High Reliability ◽  
Operational Reliability ◽  
Design Solution ◽  
Structural Factors ◽  
Factors Affecting ◽  
Braking System ◽  
Rail Vehicles

The article presents the functions of the relay valve and its place in brake systems of rail vehicles. The relay valve were divided according to their type, the structure and principle of their operation were discussed, and examples of rail vehicles and modules in which relay valves are installed are presented. Because of their function in braking systems the relay valves should be characterized by high reliability and correct carrying out the tasks in the braking system of rail vehicles. The article describes selected structural factors affecting the operation of the relay valve and which are important for ensuring the safety of train traffic. Such factors are the lubricants used in the relay valves and the way of controlling it simultaneously with two signals with the function of an alternative that eliminates unreliable elements of the braking system. The analysis of the test results of the lubricant parameters and the testing of the relay valves on the test bench showed that the correctness of the relay valves depends essentially on the properties of the lubricant used, especially at low temperatures. On the basis of the tests carried out, a grease was selected that at low temperatures meets the criteria for correct and reliable operation of relay valves in rail vehicles. In terms of the control method, a comparison of two control signal delivery systems to the relay valve has been made, a new design solution is presented that ensures greater operational reliability and thus greater safety of the train traffic.

Computer Controlled Braking System for Amtrak High Speed Trainsets

2002 ◽  
Author(s):  
Kenneth R. Hesser ◽  
Gregory A. Gagarin
Keyword(s):  
High Speed ◽  
High Reliability ◽  
Power Conservation ◽  
Pneumatic Control ◽  
Braking System ◽  
Rail Vehicles ◽  
Computer Controlled ◽  
And Performance ◽  
Electric Braking ◽  
Friction Brake

The new Amtrak High Speed Trainsets used in ACELA Express service on the Northeast Corridor are equipped with an advanced microprocessor controlled braking system with full pneumatic control back-up protection. The system is designed to provide high reliability, to prioritize high levels of electric braking from power cars on each end of the trainset and to fully blend electric braking effort with the pneumatic friction braking effort of the entire trainset. This type of control which optimizes power conservation through regenerative braking and decreases wear and thermal stress on friction brake components is similar to that used on the German Railways ICE trainsets but is totally new and unique to North American inter-city rail vehicles. This paper will describe the system, special components and performance of this equipment.

scholarly journals A Hierarchical Reliability Control Method for a Space Manipulator Based on the Strategy of Autonomous Decision-Making

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Xin Gao ◽  
Yifan Wang ◽  
Hanxu Sun ◽  
Qingxuan Jia ◽  
Gang Chen ◽  
...  
Keyword(s):  
Control Method ◽  
Control Level ◽  
Control Variable ◽  
Control Process ◽  
Operational Reliability ◽  
System Control ◽  
Related Factors ◽  
Space Manipulator ◽  
Factors Affecting ◽  
Reliability Control

In order to maintain and enhance the operational reliability of a robotic manipulator deployed in space, an operational reliability system control method is presented in this paper. First, a method to divide factors affecting the operational reliability is proposed, which divides the operational reliability factors into task-related factors and cost-related factors. Then the models describing the relationships between the two kinds of factors and control variables are established. Based on this, a multivariable and multiconstraint optimization model is constructed. Second, a hierarchical system control model which incorporates the operational reliability factors is constructed. The control process of the space manipulator is divided into three layers: task planning, path planning, and motion control. Operational reliability related performance parameters are measured and used as the system’s feedback. Taking the factors affecting the operational reliability into consideration, the system can autonomously decide which control layer of the system should be optimized and how to optimize it using a control level adjustment decision module. The operational reliability factors affect these three control levels in the form of control variable constraints. Simulation results demonstrate that the proposed method can achieve a greater probability of meeting the task accuracy requirements, while extending the expected lifetime of the space manipulator.

scholarly journals Study on Pressure Change Rate of the Automatic Pressure Regulating Valve in the Electronic-Controlled Pneumatic Braking System of Commercial Vehicle

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 938
Author(s):  
Hanwei Bao ◽  
Zaiyu Wang ◽  
Zihao Liu ◽  
Gangyan Li
Keyword(s):  
Control Method ◽  
Pressure Change ◽  
Autonomous Driving ◽  
Commercial Vehicles ◽  
Change Rate ◽  
Braking System ◽  
Theoretical Support ◽  
Automatic Pressure ◽  
Braking Process ◽  
Vehicle Dynamic Model

In contrast to the traditional pneumatic braking system, the electronic-controlled pneumatic braking system of commercial vehicles is a new system and can remedy the defects of the conventional braking system, such as long response time and low control accuracy. Additionally, it can adapt to the needs and development of autonomous driving. As the key pressure regulating component in electronic-controlled pneumatic braking system of commercial vehicles, automatic pressure regulating valves can quickly and accurately control the braking pressure in real time through an electronic control method. By aiming at improving driving comfort on the premise of ensuring braking security, this paper took the automatic pressure regulating valve as the research object and studied the pressure change rate during the braking process. First, the characteristics of the automatic pressure regulating valve and the concept of the pressure change rate were elaborated. Then, with the volume change of automatic pressure regulating valve in consideration, the mathematical model based on gas dynamics and the association model between pressure change rate and vehicle dynamic model was established in MATLAB/Simulink and analyzed. Next, through the experimental test of a sample product, the mathematical models have been verified. Finally, the key structure parameters affecting the pressure change rate of the automatic pressure regulating valve and the influence law have been identified; therefore, appropriate design advice and theoretical support have been provided to improve driving comfort.

295. Structural factors affecting the puffing behaviour of petroleum cokes

Carbon ◽  
1984 ◽  
Vol 22 (2) ◽  
pp. 238
Author(s):  
J. Machnikowski ◽  
L. Wajzer ◽  
S. Jasieńko
Keyword(s):  
Structural Factors ◽  
Factors Affecting

The Application of S7-200 PLC Reactive Compensation Device in Small Substation

2012 ◽  
Vol 479-481 ◽  
pp. 1476-1480
Author(s):  
Qing He Chu ◽  
Wen Si Cao ◽  
Zhen Nie
Keyword(s):  
Reactive Power ◽  
Control Method ◽  
High Reliability ◽  
Reactive Power Compensation ◽  
Control Device ◽  
Reactive Compensation ◽  
Reconstruction Project ◽  
Compensation Device ◽  
And Control

In the present rural power grid reconstruction project ,according to the problems of capacitor reactive power compensation in rural small substation. Take a small substation for instance, according to its operation and control method, set the criterion of the capacitor bank switching. A new high reliability, flexible reactive power compensation control device based on s7-200 PLC is designed. It plays an important role in improving the power supply , guaranteeing the quality of voltage, reducing the loss of rural power gid.

scholarly journals The Effects of Picking Up Primary School Pupils on Surrounding Street’s Traffic: A Case Study in Hanoi

2020 ◽  
Vol 14 (1) ◽  
pp. 237-250
Author(s):  
Dinh Hiep ◽  
Vu V. Huy ◽  
Teppei Kato ◽  
Aya Kojima ◽  
Hisashi Kubota
Keyword(s):  
Primary School ◽  
Traffic Safety ◽  
Traffic Congestion ◽  
Traffic Management ◽  
Primary Schools ◽  
Traffic Accidents ◽  
Binary Logistic Regression ◽  
Binary Logistic Regression Model ◽  
Factors Affecting ◽  
Almost All

Introduction: One of the significant characteristics of schools in Vietnam is that almost all parents send their children to school and/or pick up their children from school using private vehicles (motorcycles). The parents usually stop and park their vehicle on streets outside the school gates, which can lead to serious congestion and increases the likelihood of traffic accidents. Methods: The objective of this study is to find out factors affecting the picking up of pupils at primary school by evaluating the typical primary schools in Hanoi city. A binary logistic regression model was used to determine factors that influence the decision of picking up pupils and the waiting duration of parents. The behavior of motorcyclists during the process of picking up pupils at the primary school gate has been identified and analyzed in detail by the Kinovea software. Results and Discussion: The study showed that, on the way back home, almost all parents use motorbikes (89.15%) to pick up their children. During their waiting time (8.48 minutes in average), they made a lot of illegal parking actions on the street there by, causing a lot of “cognitive” errors and “crash” points surrounding in front of the primary school entrance gate. Risky picking-up behaviors were significantly observed, i.e. picking-up on opposite side of the school, making a U-turn, backing-up dangerously, parking on the middle of street, and parking on the street next to sidewalk). Conclusion: Based on the analyzed results, several traffic management measures have been suggested to enhance traffic safety and reduce traffic congestion in front of school gates. In addition, the results of the study will provide a useful reference for policymakers and authorities.

scholarly journals Plugging Braking of Two-PMSM Drive in Subway Applications with Fault -Tolerant Operation

2016 ◽  
Vol 12 (1) ◽  
pp. 1-11
Author(s):  
Adel Obed ◽  
Ali Abdulabbas ◽  
Ahmed Chasib
Keyword(s):  
Pulse Width Modulation ◽  
Control Method ◽  
Fault Tolerant ◽  
Permanent Magnet Synchronous Motor ◽  
Voltage Source ◽  
Braking System ◽  
Simulink Model ◽  
Braking Torque ◽  
Subway Train ◽  
Electric Traction

The Permanent Magnet Synchronous Motor (PMSM) is commonly used as traction motors in the electric traction applications such as in subway train. The subway train is better transport vehicle due to its advantages of security, economic, health and friendly with nature. Braking is defined as removal of the kinetic energy stored in moving parts of machine. The plugging braking is the best braking offered and has the shortest time to stop. The subway train is a heavy machine and has a very high moment of inertia requiring a high braking torque to stop. The plugging braking is an effective method to provide a fast stop to the train. In this paper plugging braking system of the PMSM used in the subway train in normal and fault-tolerant operation is made. The model of the PMSM, three-phase Voltage Source Inverter (VSI) controlled using Space Vector Pulse Width Modulation technique (SVPWM), Field Oriented Control method (FOC) for independent control of two identical PMSMs and fault-tolerant operation is presented. Simulink model of the plugging braking system of PMSM in normal and fault tolerant operation is proposed using Matlab/Simulink software. Simulation results for different cases are given.

scholarly journals Augmented Leadframe Design for Stable Multi-Wire Ground Bonding

2021 ◽  
pp. 1-5
Author(s):  
Frederick Ray I. Gomez ◽  
Alyssa Grace S. Gablan ◽  
Anthony R. Moreno ◽  
Nerie R. Gomez
Keyword(s):  
Failure Modes ◽  
High Reliability ◽  
Semiconductor Industry ◽  
Global Market ◽  
Design Solution ◽  
Package Design ◽  
Strict Compliance ◽  
Bridge Type ◽  
Major Application ◽  
Augmented Design

Technological change has brought the global market into broad industrialization and modernization. One major application in the semiconductor industry demands safety and high reliability with strict compliance requirement. This technical paper focuses on the package design solution of quad-flat no leads (QFN) to mitigate the leadframe bouncing and its consequent effect of lifted wire and/or non-stick on leads (NSOL) defects on multi-wire ground connection. Multi-wire on single lead ground (or simply Gnd) connection plays critical attribute in the test coverage risk assessment. Cases of missing wire and/or NSOL on the multi-wire Gnd connection cannot be detected at test resulting to Bin1 (good) instead of Bin5 (open) failure. To ease the failure modes mechanism, a new design of QFN leadframe package with lead-to-diepad bridge-type connection was conceptualized for device with extended leads and with multiple Gnd wires connection. The augmented design would provide better stability than the existing leadframe configurations during wirebonding. Ultimately, the design would help eliminate potential escapees at test of lifted Gnd wire not detected.

Study on Quality Control Method in Multi-Specification and Small-Batch Production

2014 ◽  
Vol 1006-1007 ◽  
pp. 363-366
Author(s):  
Hai Dong ◽  
Qing Quan Tong ◽  
Yi Kai Wang
Keyword(s):  
Quality Control ◽  
Process Control ◽  
Control Chart ◽  
Control Method ◽  
Quality Characteristics ◽  
Batch Production ◽  
Factors Affecting ◽  
Quality Control Method ◽  
Element Theory

Aiming at the problem of less quality characteristics data in multi-specification and small-batch production, matter-element theory was applied to adjust similarity of factors affecting the quality during the processing, thus similar processes was divided and data shortage problem was resolved. In addition, the relative range method was applied to translate characteristics data, thus drawing the control chart to judge process control state.Through the analysis of a case,the validity of quality control method was verified in the multi-specification and small-batch production.

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