Ultrasonic Monitoring System For Railway Tracks

Table of contents

List of figures

Abstract

1. Introduction

1.1Motivation and Background

2. Design (Overview)

2.1 Approach

2.2 Methodology

2.2.1Concept (Scenarios)

A.full broken track

B. Minor cracks

C. Monitoring zones

3. Design (High level scope)

4. References

List of figures

Figure 1 Proposed design (Overview)

Figure 2 Block diagram of ultrasonic

Figure 3 Operation of burst timing block

Figure 4 Transmitter Tx sending Ultrasonic pulse received by Rx

Figure 5 Transmitting power versus frequency

Figure 6 received sine signal of 40 kHz

Figure 7 Working mechanism indicating missing track or full crack

Figure 8 Working mechanism indicating minor crack interfering with the wave

Figure 9 Zone Monitored

Abstract

Ultrasonic system provides early warning of anomalies within the railway track; this provides mitigation against the risk of derailment due to a broken rail whereby some common rail defects include squats, wheel burn, inclusions and surfacecracking where 90% is due to cracks on the rails either due to natural causes or due to antisocial elements. Railway tracksarethen subjectedto very large forces even when operated undernormal traffic conditions and exposed to potential extremes of temperature from ourenvironment. Thus the intendedpurpose ofthis report is to present different scenarios of the Ultrasonic monitoring railway tracks (full crack, minor crack and zone fully monitored) for Transnet (RSA,Johannesburg) and to itemize several design materials (transmitter, receiver, PLC, GSM, etc.).

1. Introduction

1.1Motivation and Background

Transnet is a South African parastatal company, of which its business is based on freight logistics chain that delivers goods around the country. It is currently the only business which is in control of the railways infrastructuresystem within South Africa. The company has got five divisions, in which the freight rail division is the largest.This division has been facing significant security and safety challenges, which are posing operational danger to the business and safety of personnel. Currently it is spending an average of R800 million every year on operation occurrences and security-related incidence, of which 50% of this is due to Theft of assets and derailment. To assist minimise or eliminate the crucial part of these challenges, which is the problem of derailment of trains due to railway tracks theft and broken tracks, the team developed this business plan which instigate control measures to overcome the problem.

These challenges are split into two broad areas, which is the operational occurrences (safety incidents) and security-related incidents entailing twelve and nine categories respectively. The two areas, categories and safety statistics have been extracted from the Railway Safety Regulator (RSR) report which fulfils the legislative requirement contained in the National Railway Safety Regulator Act, Act 16 of 2002.Our company identified thischallenge as an opportunity to prepare a business plan focusing on researchinginto measures to eliminate or minimise trains’ derailment, in-turn propose and present a feasible design plan and business model.

1. 2 Objectives

Derailment due to cracks and Railway Tracks Theft

- Quantify extant of theft and cracks
- Evaluate affected areas/routes
- Evaluate old system
- Develop new system
- Conduct trial/testing
- Develop Business case

Process improvement

- Evaluate current processes
- Identify Gaps
- Analyse Gaps
- Develop Solutions
- Trial proposed solution
- Implement solutions
- Evaluate Costs
- Monitor and track solution

2. Design(Overview)

2.1 Approach

The Ultrasonic Rail Detector is designed to reliably detect breaks in train rails under all environmental conditions; is the first and only alternative broken rail detection system developed, produced and implemented on a large scale.

Materials (Design Inclusion):

- Ultrasonic (40KHz) Transmitter
- Ultrasonic (40KHz) Receiver
- Microprocessor (controller)
- Global System for Mobile Communication Module (GSM)
- Existing Programmable Logic Controller (PLC)
- Cabinet with Power Supply and Communication Equipment
- Alarm Terminal

Figure 1 Proposed design (Overview)

Abbildung in dieser Leseprobe nicht enthalten

The system is designed to operate from solar power and to monitor the full length of each railway track for any broken track. Transmitter bi-directional insert coded ultrasonic signals into both rails; these signals are received and processed by receivers to determine the position, time of arrival, and integrity of the signal.

The following are the advantages of the proposed design:

- Easy installation of materials
- No track modification
- Section coverage up to 20km
- Low maintenance cost
- Easy fitting and removal of rail mounted ultrasonic transmitters and receivers

Figure 2 Block diagram of ultrasonic

Abbildung in dieser Leseprobe nicht enthalten

2.2 Methodology

The operation of the system is based on a simple transmit-receive confirmation protocol whereby acoustic signal is generated and inserted in the rail at one location (transmitter), propagates along the rail, and is received at a remote location (receiver). The integrity of the rail between the transmitter and receiver is confirmed as long as an acceptable signal is received.

Then to enable Receivers to determine the direction from which acoustic energy originates, Transmitters insert a burst train consisting of 5 pulses at a preset Burst Repetition Interval (BRI) into the left rail, followed by a sequence at a different Burst Repetition Interval into the right rail [1].

Figure 3 Operation of burst timing block

Abbildung in dieser Leseprobe nicht enthalten

Damages

1. Analyse information to determine number of incident & quantify rand value impact
2. Determine common incident areas/routes, create high theft zone areas.
3. Evaluate old system in order to determine short fall or gaps.
4. Design a cost effective monitoring system to highlight quadrants that are affected by theft and improve response times.
5. Conduct Testing. Testing to commence in areas identified as high value/incidents areas.
6. Conducts trials. Trials will commence in areas/routes to determine if the solution is feasible and effective

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