Description:TECHNICAL FIELD OF INVENTION
The present invention relates to sensing technology. More particularly, the present invention relates to a system (A) for monitoring and detecting load variations in railway freight wagons and containers. The system(A) aids in real time measurement of static and dynamic loads of railway freight wagons and containers. Moreover, the invention relates to a method to detect uneven load distributions and type of distribution in railway freight wagons and containers.
BACKGROUND AND PRIOR ART
Railway freight operations play a critical role in the transportation of goods across vast distances, requiring efficient and reliable systems to ensure safety, optimize loading, and maintain operational efficiency. Monitoring the load distribution in railway wagons is vital for ensuring the structural integrity of the wagons, preventing accidents, and improving overall railway management. Overloading or uneven loading in freight wagons and containers can lead to structural damage, derailments, instability, accelerated wear and tear on both infrastructure and rolling stock, and increased maintenance costs. Traditional load measurement techniques, such as strain gauges and accelerometers, often fall short in terms of precision, durability, environmental adaptability, and the ability to measure loads while in motion. Also, traditional methods involve manual inspection, static weighing systems at designated locations, or mechanical load sensors which may require train stoppages being labor-intensive, and providing data that is often neither real-time nor precise. Moreover, mechanical systems are prone to wear and tear, leading to reduced reliability and increased maintenance demands.
Patent document EP 2902752 B1 titled, “Railway Freight car on-board weighing system” utilises strain gages and/or displacement transducers for measuring the load of a railway car. Strain gauges and electronic transducers are susceptible to electromagnetic interference, which can distort the signal in environments with strong electromagnetic fields. Strain gauges without proper encapsulation, can degrade in humid or corrosive environments.
Prior art document, CN113670424A titled, “Optical fiber sensor installed on truck and used for measuring overload and unbalance loading of truck and system,” focuses on the application of Fiber Bragg Grating sensors for measuring overload and unbalance loading of truck. The monitoring system requires adoption of temperature sensors for correction of temperature deviation of the sensors for accurate monitoring. Temperature sensors are provided at the left suspension and the right suspension of the vehicle along with the optical sensors for respective temperature corrections of the fiber Bragg grating- optical sensors.
Prior art document, CN101672687B titled, “Device for testing railway wagon overloading and unbalance loading by foundation less-tunnel fiber and method,” proposes a device for detecting overload and partial load of railway freight cars without foundation pit fiber, which is composed of a light source, a coupler, ten fiber Bragg grating strain sensors, spectroscopic device, wavelength demodulation device, data collector and analysis processing device. The device employs ten fiber grating sensors for detection but does not aid to identify uneven loading across the left/right, front/back, diagonal, or central regions or real time data acquisition for accurate monitoring of the railway wagon.
There is a need to develop a facile system and method which can measure uneven loading of railway freight wagons and containers on real time basis with accuracy.

STATEMENT OF INVENTION
Accordingly the present invention provides-
A portable system (A) for real time detecting, measuring, and monitoring load variations in railway freight wagons and containers, comprising quadruple optical sensors (101) each housed on a clamp (112), an interrogator (102) and a Data processing unit (107); wherein-optical sensors (101) are connected to the Data processing unit (107) through interrogator (102) and optical sensors (101) housed on the clamp(112) are accommodated between sleepers(104) on each rail on which the railway freight wagons and containers are in motion.
A method for real time detecting, measuring, and monitoring load variations in railway freight wagons and containers adopting system (A) of present invention, said method comprising acts of-
a) detecting vertical strain induced by wheel loads of freight wagon and containers on optical sensors(101) as shift in wavelength,
b) capturing shift in wavelength of optical sensor through Interrogator (102) and converting into digital signals,
c) sending the digital signals to Data Processing Unit (107) for processing, wherein
i. load distribution across the wheels and tracks of railway freight wagon and containers is calculated,
ii. identifying load variation, and
iii. comparing results against user-defined thresholds to detect anomalies,
and
d) uploading the processed data to cloud server(111) for storage, alerting and/or reporting on detection, measurement and monitoring of load variation in railway freight wagons and containers.
BRIEF DESCRIPTION OF FIGURES
The appended figures form part of specification. The features of the present invention can be understood in detail with the aid of figures, in combination with the detailed description of the specific embodiments presented herein. It is to be noted, however, that the appended figures illustrate only typical embodiments of this invention and therefore, not to be considered limiting of its scope for the invention.
Figure 1A: illustrates the portable system (A) for measuring, monitoring and detecting load variations in railway freight wagons and containers.
Figure 1B: illustrates installation of sensor with clamp.
Figure 2: illustrates the connection of the sensor (A) with network
Figure 3: illustrates the four wheels of railway freight wagon on right and left side of railway track
Figure 4: depicts uneven loading pattern.

DETAILED DESCRIPTION OF INVENTION
The foregoing description of the embodiments of the invention is presented for the purpose of illustration. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, as many modifications and variations are possible in light of this disclosure for a person skilled in the art in view of the figures, and description. It may further be noted that as used herein, the singular “a” “an” and “the” include plural reference unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by a person skilled in the art.
The present invention provides a portable system (A) for real time measuring, monitoring and detecting uneven load variations in railway freight wagons and containers; and identifying potential risks of derailment or railway track degradation.
The portable system (A) of present invention is simple to instal with lower maintenance costs and provides real-time alerts ensuring proactive responses to load imbalances or uneven loads.

Figure 1A illustrates the portable system (A) for measuring, monitoring and detecting load variations in railway freight wagons and containers and figure 1B illustrates the installation of sensor on clamp. The system(A) comprises quadruple optical sensors (101) each housed on a clamp (112), connected to an interrogator (102) and Data processing unit (107); wherein dual optical sensors (101) housed on the clamp(112) are placed on each rail on which the railway freight wagons and containers are to be measured, monitored and detected for load variations while in motion.

In an embodiment of the invention, the optical sensors(101) housed on the clamps (112) are fixed on to the bottom of the rail (103) on which the railway freight wagons and containers are to be measured, monitored and detected for load variations, while in motion. The sensors(101) under the rails(103) detect vertical strains induced by wheel loads of railway freight wagons and containers.

In another embodiment of invention, the clamps (112) with optical sensors (101) are fixed at a distance of 1800mm from one another on each rail (103) between the sleepers (104), optical sensors (101) are fixed three (3) sleepers away from one another on each rail (103). Normally sleeper to sleeper distance is around 600mm, accordingly distance between the clamps (112) is 800mm.
In an embodiment of invention, the Interrogator (102) captures the wavelength shifts from the optical sensor at a fixed sampling frequency rate of 500Hz.
In an embodiment of invention as illustrated in the figure 2, the Interrogator (102), captures, converts and encodes the wavelength shifts from the optical sensor into digital data and sends it to Data Processing Unit (DPU) (107) comprising necessary algorithms/software.
In an embodiment of invention the DPU(107) does the signal conditioning and applies the algorithms to measure the load on each wheel of the railway freight wagon and container; and measures direction, speed, and uneven loading pattern. The DPU(107) sends the processed data to the cloud server (111) through an Internet Router (109) via the Internet (110). Ethernet switch (108) provides Local Area Network functionality and connects the Interrogator (102), DPU (107), and Internet Router (109) in a common network ( figure 2).
In an embodiment of the invention, the optical sensor is a Fiber Brag Grating (FBG) Sensor for measuring real time strain caused by wagon load variations through shift in the wavelength.
In an embodiment of invention, as the optical sensor experiences strain due to load on a rail, the spacing of the grating changes, leading to a shift in the reflected wavelength and provides a precise, quantifiable measure of strain.

In an embodiment of invention, each optical sensor is designed to reflect light at a specific baseline wavelength, typically in the range of 1528 nm to 1568 nm, depending on the grating spacing.

In an embodiment of invention, when strain is applied, the grating spacing changes, resulting in a shift of the reflected wavelength; a positive strain (tension) increases grating spacing, leading to a longer wavelength and a negative strain (compression) decreases grating spacing, resulting in a shorter wavelength.
Typically, the shift is proportional to the amount of strain experienced by the optical sensor. A typical sensitivity range is around 40 pm/ton (picometers per ton)
For example if a railway wagon or container each wheel passes over the sensor causing 600pm wavelength shift it will correspond to (600/40) = 15tons. Each wheel weight of a freight wagon is calculated separately from said information using the formula mentioned below and load distribution within the wagon is calculated.
The present invention also relates to a method of detecting uneven loading patterns in railway freight wagons and containers adopting system(A). The flowchart (A) schematically depicts said method.
The method comprises steps of-
Step 1: Data Collection involving optical sensors (101)and Interrogator(102).
a) Optical sensors of the system (A) under the rails detect vertical strains induced by wheel loads of freight wagon and containers.
b) As the railway freight wagon and containers passes, strain variations cause wavelength shifts in the sensors.
c) The Interrogator(102) captures these shifts in real-time, converting them into digital signals for processing.
Step 2: Data Processing and Load Analysis involving Data processing unit-DPU (107)
a) The digital signals from the Interrogator (102) are sent to the DPU.
b) Using algorithms, the DPU:
(i) Calculates load distribution across all wheels and tracks , L1-L4, R1-R4 of the railway freight wagon.
(ii) Identifies left/right, front/back, diagonal, and center load imbalances.
(iii) Compares results against user-defined thresholds to flag anomalies.
Step 3: Real-Time Alerts involving cloud server
a) Processed data is uploaded to the cloud server for storage and visualization.
b) The cloud server(111) provides:
(i) Reports on load conditions, railway wagon speed, and historical trends.
(ii) Real-time alerts to maintenance teams/personnel to ensure proactive maintenance and safety management.
In an embodiment of invention, the portable system (A) is strategically placed in a localized measurement zone under the rails to detect vertical strain caused by wheel loads of railway freight wagons. The measurement zones may be repeated along the railway line as needed based on operational requirements and safety considerations.
In another embodiment of invention, Finite Element Analysis (FEA)- a computational modelling technique/software is employed to simulate and understand the strain and stress distributions on railway tracks under various loading conditions. FEA ensures that the sensor location of system (A) capture subtle variations in strain, improving the detection and measurement of uneven loading. The FEA software divides the railway track into smaller elements (finite elements) and calculates the strain and stress at each element. The results help identify high-strain zones where FBG sensors should be placed for maximum accuracy.

Flow chart-A

In an embodiment of invention, the load distribution is monitored by the portable system (A) through the optical sensors placed along the left (L) and right (R) rails. A railway freight wagon and containers have eight wheels four wheels on the left marked as L1, L2, L3, and L4, and four wheels on the right marked as R1, R2, R3, and R4 as depicted in the figure 3.
The system(A) calculates loads as given below:
-Left/Right Load: Total load on the left (X) = (L1 + L2 + L3 + L4) and right (Y) = (R1 + R2 + R3 + R4) sides of the track.
-Front/Back Load: Total load at the front (X) = (L1 + L2 + R1 + R2) and back (Y) = (L3 + L4 + R3 + R4) of the train.
-Diagonal Load: Left diagonal (X) = (L1 + L2 + R3 + R4) and right diagonal (Y) = (R1 + R2 + L3 + L4).
-Center Load: Ratio of front-to-back load at the center.
The system compares the two loads X and Y, categorize the uneven loading pattern as shown in Figure 4. The allowed load variation percentage is programmable by the user. If the variation of the two loads exceeds the allowed variation, it generates a report with an alert.
The table 1 below provides a sample report generated by the system (A).

In said table, rows 19, 20, 21 and 22 form wagon number 4 (W4). There are 4 wheels on the left and 4 wheels on the right. The load is calculated for each wheel and listed in the columns left wheel average dynamic load and right Wheel average dynamic Load. As per the equations listed above Left Load (X = 28.93Ton) & Right Load (Y=33.13), Front Load (X=34.25) & Back Load (Y=21.08) are calculated. In this example tabulated above, the ratio of Front Load (X=34.25) to Back Load (Y=21.08) is 62% which is more than the configured threshold limit of 25%. Hence it is indicated as Font loaded Wagon.
Thus the invention provides the advantage of seamless integration of the system (A) with the railway track for a cost effective method of detection and measurement of uneven loading of railway freight wagons and containers. The system (A) aids in real-time monitoring with predictive analytics for comprehensive railway safety.
, Claims:WE CLAIM
1. A portable system (A) for real time detecting, measuring, and monitoring load variations in railway freight wagons and containers, comprising quadruple optical sensors (101) each housed on a clamp (112), an interrogator (102) and a Data processing unit (107); wherein-
optical sensors (101) are connected to the Data processing unit (107) through interrogator (102) and optical sensors (101) housed on the clamp(112) are accommodated between sleepers(104) on each rail on which the railway freight wagons and containers are in motion.
2. The portable system (A) as claimed in claim 1, wherein the Data Processing unit (107) is connected to a cloud server (111) through internet server (109) for processing data.
3. The portable system (A) as claimed in claim 2, wherein the processed data from cloud server(111) is generated as a report on load variation.
4. The portable system (A) as claimed in claim 1, wherein dual optical sensors (101) each housed on the clamp (112) are accommodated between sleepers(104) on each rail.
5. The portable system (A) as claimed in claim 1, wherein dual optical sensors (101) are fixed at a distance of 1800mm between each other.
6. The portable system (A) as claimed in claim 1, wherein the optical sensor (101) housed on the clamp (112) is a Fiber Bragg Grating sensor.
7. The portable system (A) as claimed in claim 6, wherein the optical sensor (101) reflect light at a baseline wavelength ranging from 1528 nm to 1568 nm.
8. The portable system (A) as claimed in claim 6, wherein the Fiber Bragg Grating sensor measure real time strain caused by wagon load variations through shift in its wavelength.
9. A method for real time detecting, measuring, and monitoring load variations in railway freight wagons and containers adopting system (A) of claim 1, said method comprising acts of-
a) detecting vertical strain induced by wheel loads of freight wagon and containers on optical sensors(101) as shift in wavelength,
b) capturing shift in wavelength of optical sensor through Interrogator (102) and converting into digital signals,
c) sending the digital signals to Data Processing Unit (107) for processing, wherein
i. load distribution across the wheels and tracks of railway freight wagon and containers is calculated,
ii. identifying load variation, and
iii. comparing results against user-defined thresholds to detect anomalies,
and
d) uploading the processed data to cloud server(111) for storage, alerting and/or reporting on detection, measurement and monitoring of load variation in railway freight wagons and containers.
10. The method as claimed in claim 9, wherein the load variation is due to left, right, front, back, diagonal, and/or center load distribution.