taking control over railroad and enhancing rail safety with simulation

Taking Control over Railroad and

Enhancing Rail Safety with

Simulation Solutions

Railway systems make up a highly complex transportation infrastructure network comprising of elements such as trains, tracks, railroad switches, signals, rail yards and many others. As a multi-element system, railway should be viewed from a system-wide perspective while planning, constructing, and maintaining it. With rail systems being used to transport freight, including passengers and hazardous materials, on tracks designated for heavy rail, the demands for accident-free rail systems only become more complex. In order to improve safety in railway traffic, different innovative approaches to testing rail systems are called for. This paper focuses on simulation as an effective method of testing rail systems.

Increased Railway Safety Concerns Fundamental Challenges in Rail Systems Testing Testing through Life Cycle: V-model Test Strategies for Rail SystemsTesting of SubsystemsDevelopment of Signaling Systems Development of Rail VehiclesDevelopment of Back Office SystemsFactory Acceptance TestingRegression TestingUser TrainingBenefits of Simulation TestingConclusionReferences

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CONTENTS

Professional Software Associates, Inc.

Taking Control over Railroad and Enhancing Rail Safety with Simulation Solutions

Managing safety on the rail network presents a major challenge to the rail industry as it faces pressures from rising numbers of passengers and high-speed trains. Nowadays, trains can travel faster, are heavier, and require a greater distance to stop. Possibilities for accidents include derailment, head-on collision with other trains traveling the opposite direction, and collision with automobiles at a level crossing. Level crossing collisions are relatively common in the United States, resulting in death for about 500 people each year. [1] Overall, the number of railroad deaths is increasing – in 2013 an increase of 6 percent was observed. [2]

According to the Federal Railroad Administration, in an average year in the United States, more than 3,000 train accidents occur, leading to death, injury, or property damage. For example, four trains hauling crude oil have derailed in the U.S. and Canada since mid-February 2015, rupturing tank cars, spilling their contents, polluting waterways and igniting massive fires that burned for days. The derailments have deepened safety concerns specifically, if an oil-train accident were to occur in a populated area, the results could be disastrous. [3]

For railway operations to run safely, efficient testing processes and software tools are required. They allow for the timely detection of discrepancies and different kinds of problems for the purpose of their troubleshooting, as well as security and performance monitoring. Inaccurate testing may lead to railroad accidents and human losses, the cost of which is too high.

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Increased Railway Safety

Concerns


New rail systems are being developed or existing systems being updated and delivered globally, each installation having unique requirements with different configurations needing to be tested. Rail testing has become increasingly important as the complexity of railway systems increases. Every day around the world, rail test engineers are challenged to measure, evaluate, and validate increasingly complicated designs to achieve the highest standards of efficiency and safety. In order to ensure proper operation for vehicles on the track, significate efforts are put into the testing process.

The tremendous size of railway systems creates a new, daunting challenge for testing specialists. The United States has the largest railway system in the world - nearly 240,000 km of track, which is enough to circle the Earth five times. [4] Now imagine how much time and effort is required to test each element of the system to ensure that it is functioning correctly, as a part and as a whole system.

Apart from the challenges related to the railway structure and size mentioned earlier, lack of qualified skilled technicians could be a major problem in rail systems testing. There are a limited number of specialists who possess in-depth knowledge in both programming and railway systems, which is required of rail test engineers. A specialist with a set of necessary skills and deep domain expertise is capable of conducting more comprehensive rail testing in less time, thereby saving on cost and providing better test results.


Fundamental Challenges in Rail Systems

Testing


Among the variety of current test models, V-model has proven itself to be one of the most comprehensive testing strategies used as part of a development cycle.

Just like the Waterfall model, the V-shaped life cycle is a sequential path of execution of processes. Each phase must be completed before the next phase begins. This model emphasizes testing, and ensuring that the product of each phase is error-free before moving to the next stage. It confirms that corrections are not needed in later phases, thus avoiding costly repairing. V represents the sequence of steps during development, the activities to be performed, and the results produced. The left side of the V describes the decomposition of requirements and system specification; the right side represents the union of parts and their validation. Namely, these are referred to as verification and validation phases.


Testing through Life Cycle: V-model


Diagram of V-model

The V-model of testing offers a considerable range of benefits over others, as it emphasizes the building of test data and test scenarios during development and not as an afterthought. The V-model also allows proactive defect tracking, which is crucial to the testing of such complex systems as railway. Cost of defect resolution increases with every stage. Early detection has positive benefits on the cost of system development and limitations on delays in system deployments.

VerificationPhase

ValidationPhase

BRS (Business req.specifications)

SRS (System req.specifications)

HLD (High level design)

LLD (Low level design)

Coding

CODE

Unit Testing

Component Testing

System IntegrationTesting

System Testing

Acceptance Testing




The choice of test strategy is a key factor in the success of testing efforts and the accuracy of test plans. Various approaches for evaluating the performance of vehicles and their components have been proposed and put into actual practice; they can be conventionally divided into two groups:

1. Testing using real components.2. Testing using computer simulators designed to provide a realistic imitation of realcomponents.

The first group of methods includes unit test on test beds, test run on in-plant tracks, and trial runs on commercially operated lines. This testing approach implies high expenditure of man power, equipment and results in cost and lengthier project deliveries.

Another approach to rail testing, which has been used lately, encompasses computer-based simulation models of the real rail systems and components. This allows the simulation user to examine complex behavior and scenarios, on a wide range of conditions, far more quickly and inexpensively than with physical systems.

Test Strategies for Rail Systems


Rail systems today are complex and incorporate many subsystems, which concur together in delivering a high-quality transportation solution. Failure of any of such subsystems can have a devastating impact on the service itself, with obvious deterioration of performance, reduction of perceived quality and increment of costs. This is what makes it so important to test subsystems as a prelude to system testing, and this is where simulation methods can be implemented.

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Testing of Subsystems

Development of Signaling Systems

Development of Rail Vehicles

Development of Back Office Systems

Factory Acceptance Testing

Regression Testing

User Training


Simulation testing methods can be broadly applied in the rail industry and can successfully be used for testing at all stages of verification and validation. The use of simulation results in a reduction in cost, improved quality, and time savings to get a fully commissioned system deployed. Practical use of rail simulation solutions include the following cases described below:


Railway signaling is a system used to safely direct railway traffic in order to prevent trains from colliding. As the complexity of signaling systems increases, it is important to ensure that planned new and/or improved engineering works will deliver the desired system performance improvements. Simulators are designed to validate railway signaling and interlocking systems, and thus help to enhance railroad operations safety. The simulation of interlocking systems, designed to prevent conflicting actions related to the position of switches and signals, is especially advantageous for uncontrolled railway segments, where there is no dispatcher.

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Regression Testing

User Training



From light rail to locomotives, every rail vehicles is designed to run safely and smoothly on tracks. To enable optimal operational performance with the highest level of reliability and safety, simulation solutions can be used during the development of rail vehicles. Usage of simulation technology results in enhanced rail vehicle operations as well as cost-efficiency.

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Regression Testing

User Training



The primary function of the back office systems is to communicate and coordinate data to and from the wayside, and train specifics to the operational and most importantly safety aspects, to help with the safe and efficient movement of trains. [5] The simulation subsystem of the back office is usually developed to ensure that the safe flow of critical information between the subsystems occurs, and the back office server (BOS) provides this functionality.

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Regression Testing

User Training

Development of Back Office

Systems


Factory acceptance testing (FAT) is necessary to carry out if the system under development is complex and the architecture is using redundant arrangements, just like most of rail systems. A FAT takes place before installation of the system and aims at verifying whether the system meets the pre-set specifications and is fully functional. It is usually carried out in several stages: a check of completeness, a verification against contractual requirements, a proof of functionality and a final inspection. Most FATs are conducted using a simulated system or part of the real system that will be used for final installation. Simulation is often implemented at the stage of the proof of functionality and results in faster and more cost-effective testing, as well as the improved quality of a system.

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Regression Testing

User Training

FactoryAcceptance

Testing


Regression testing seeks to uncover new software bugs in existing functional and non-functional areas of a system after changes have been made. With systems deployed in the field, it can be expensive to maintain physical hardware that would allow for full regression testing of system updates before they are deployed. Using a simulator of physical hardware could be an essential tool for faster and more efficient regression testing.

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Regression Testing

User Training

RegressionTesting


Simulation for training purposes is another area where rail simulators demonstrate their effectiveness. In 2004, 53% of the railway switching yard accidents (excluding highway-rail crossing train accidents) in the United States were due to human factor causes, and rail simulators are able to reduce these numbers. [6] They make it possible to work in situations that closely approximate reality, thus creating an opportunity for railway staff to practice resolving potentially critical situations which train traffic controllers and train drivers could face while going about their everyday activities. For training purposes, an instructor draws from a large range of scenarios, including signal, train and track related failures, train delays and cancellations, and monitors their resolution by operators. Faced with occasional and regular incidents and faults during the training period, the trainee acquires the knowledge and skills necessary to carry out his work.

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Regression Testing

User Training

UserTraining


Used for testing purposes, railway simulation offers considerable amount of advantages as opposed to live testing methods:

Cost. Testing of real railway is extremely expensive; computer simulation is used to cut costs dramatically.

Time. In the real world evaluating the performance of railway can take months, but simulation allows doing this earlier, during system development and faster, resulting in time to deploy being reduced.

Size. As mentioned above, the enormous size of railway presents challenge to test engineers, but rail simulator is a small-size system.

Accessibility. Simulation is used when the real railway system or its components cannot be used; because it may not be possible to shut down an existing system for testing or it is being designed but has not yet be built.


Cost

Time

Size

Accessibility

Control

Accuracy

Safety

Regression

Benefits of Simulation Testing


Control. With computer simulation, engineers can test railways on thousands of different conditions and combinations. In each case, the model simulates real life situations and allows conducting a wide range of experiments with no impact on real components.

Accuracy. Rail simulation provides the ability to find out any problems in the behavior of a system efficiently, reducing the number of errors being detected at later stages of development or deployment.

Safety. Simulation allows testing without affecting operational safety, while testing an operational railway may be hazardous.

Regression. Repetition of testing to ensure that changes within system have not adversely affected system behavior.


Cost

Time

Size

Accessibility

Control

Accuracy

Safety

Regression

Benefits of Simulation Testing


Simulation has proven itself to be a very efficient solution as the complexity of rail systems increases. The benefits of simulators are mostly seen in the process of development and testing of such complex systems as signaling, dispatching, control, and various back office systems. A high quality simulation environment can help to improve the supervision and control of railways, enhance railroad safety, and boost operational efficiency at a lower cost. It is, therefore, in the best interests of rail companies to invest into simulation for achieving the desired success in railway development and deployment.

With decades of railway experience and knowledge, Professional Software Associates advocates simulation technologies for increased safety in railway systems and improved efficiency. PSA has successfully completed many rail Industry technology projects for some of the largest rail development companies in the world, helping them achieve success in the transportation business.


Conclusion


[1] http://safetydata.fra.dot.gov/officeofsafety/default.aspx[2] http://utu.org/2015/02/04/ntsb-says-drop-in-transportation-deaths-rail-deaths-rise/[3] http://www.businessinsider.com/heres-why-so-many-oil-trains-have-derailed-this-year-2015-3[4] http://www.uic.org/spip.php?article1353[5] http://www.getransportation.com/its/positive-train-control/back-officecontrol-center[6] http://link.springer.com/chapter/10.1007/978-1-84628-812-8_6#page-1


References

Contact us:

Professional Software Associates, Inc.414 Lake Nepessing RoadLapeer, Michigan 48446 USATelephone: + 1 810 969 4222E-mail: [email protected]: www.psa-software.com


About Professional Software Associates, Inc.

Professional Software Associates (PSA) is a leading software, hardware, and product engineering company that provides comprehensive development services. PSA specializes in developing innovative products and solutions for domestic and foreign customers, using quality process standards to ensure successful delivery of software, hardware, and turnkey products to our customers.

taking control over railroad and enhancing rail safety with simulation

Documents

rail safety

new rail systems

rail network

rail industry

heavy rail

rail yards

accidentfree rail systems

existing systems