FIELD OF INVENTION
The present invention generally relates to hot metal logistics in steel plants. More
particularly the invention relates to a method for automatic tracking of the
movement of torpedo ladles carrying hot metal in the steel plant.
BACKGROUND OF INVENTION
Hot metal Logistics is one of the highly challenging areas in steel plants in
particular to keep a track of the molten iron. Incidentally, the hot metal logistic is
a process of tracking and checking whereabouts of the vessels carrying the
molten metal. The major limitation of hot metal logistics is the extreme
environmental conditions prevalent in the plant location such as high
temperature, humidity and so on. Torpedo Ladles are normally used for
transporting the hot metal from and to different locations in the plant. The
torpedo ladles are large vessels used in the transportation of hot and molten iron
from one place to the other. Hence, keeping a track on the movement of these
vessels are important in evaluating the logistics of the hot metal and also
trafficking of the torpedo ladles.
Various techniques are used for the hot metal logistic, one such technique being
Radio frequency methods of hot metal logistics.
The conventional tracking system often utilizes Radio Frequency ("RF") tags
attached to assets (e.g., a computer, a mechanical device, machinery,
equipment, etc.) to identify, locate or track such assets. One of the major

benefits of such an RF tracking system is that a line of sight ("LOS") between an
RF reader or interrogator and the RF tag is not required for communication. This
allows a large group of assets to be entered into the RF tracking system without
any significant handling. In contrast to the RF tracking system, another prior art
system for example, a bar code tracking system requires the LOS between a bar
code reader and a bar code. Thus, either personnel or a mechanical asset is
required to register the asset with the bar code tracking system. The registration
may be done by, e.g., placing the bar code in front of the bar code reader.
Another advantage of the prior art RF tracking system is that the RF tags to
some extent, are capable of surviving hostile environments, while the bar code
may be easily damaged. These features make the RF tracking system more
robust and easier to manage than the bar code tracking system.
However, even the RF tracking systems have their own disadvantages. For
example, one of the disadvantages of the conventional RF tracking system is a
trade-off between the accuracy in locating the RF tags and their operating range.
The ability to locate remote or far away RF tags comes at the expense of
accuracy in determining their location. A main contributor to this trade-off is a
multipath spreading which is relatively significant in Wide Wireless Area Networks
("WWANs"). On the other hand, in Local Wireless Area Networks ("WLANs"),
multipath signals are spread over a much smaller time range, and thus, the
achieved accuracy is much greater. The problem with the WLANs is that it is
inefficient to send requests to a large number of WLANs to determine a location

of a particular asset with the RF tag. Therefore, there is a great need for a high-
accuracy RF tracking system for locating remote or far-away assets having the
RF tag.
US 7019633 B2 discloses a RF-tracking system and method for tracking an asset.
The system includes an RF tag coupled to the asset; a wireless wide area
network ("WWAN") including a plurality of transceivers and having a first
coverage area; and a plurality of wireless local area networks ("WLAN"). Each of
the WLANs has a second coverage area within the first coverage area. In
addition, the system includes a computer which communicates with the WWAN
and the WLANs. The computer generates a signal to be transmitted to the asset
using a first transceiver of the WWAN. The asset receives the signal and
generates a response signal; the asset transmits the response signal to a
particular WLAN within which second coverage area the asset is located via a
plurality of second transceivers. The computer determines the location of the
asset within the second coverage area as a function of the response signal.
The Radio frequency (RF) tags which transmit a particular frequency
corresponding to the number of the torpedo are fixed on the torpedo. A tag
master which receives the signals from the RF tags when the tag is in the vicinity
of the tag master, and then decodes the torpedo number and thus, tracking the
presence of the torpedo. The major limitation of using RF tags on torpedoes is
that the RF tags would not be able to withstand the extreme environmental
conditions in the steel plant. This would require the repeated changing of the RF
tags thereby, increasing recurring costs.

OBJECTS OF THE INVENTION
It is therefore an object of the invention to propose a method for automatic
tracking of the movement of torpedo ladles carrying hot metal in steel plants,
which eliminates the disadvantages of prior art.
Another object of the invention is to propose a method for automatic tracking of
the movement of torpedo ladles carrying hot metal in steel plants, which adapts
a modified image processing technique to provide a fast and accurate tracking
results.
A still another object of the invention is to propose a method for automatic
tracking of the movement of torpedo ladles carrying hot metal in steel plants,
which is capable to operate under harsh environmental conditions.
Yet another object of the invention is to propose a method for automatic tracking
of the movement of torpedo ladles carrying hot metal in steel plants, which is
enabled to determine the complete movement cycle of a torpedo vessel to
provide improved logistical support to the plant.
A further object of the invention is to propose a method for automatic tracking of
the movement of torpedo ladles carrying hot metal in steel plants, which is easy
to implement and cost effective.
SUMMARY OF INVENTION
Image processing technique per se are known, and applied to various areas
nowadays. In its basic form, an image processing technique constitutes a subset

of machine vision whereby, a camera is used for obtaining images, which are
then processed by using various algorithms to obtain the desired information
from the images. According to the invention, an image processing technique is
applied for tracking the torpedo ladles. A specific BINARY ENCODED plate is
used, in which there are at least three identification marks in the form of crosses
and in between, there are binary encoding in the form of slots. The plate is made
from solid iron plates and hence, there is no problem about harsh environmental
conditions or dust and dirt accumulation.
The two crosses on one side of the plate and a single cross on the other side,
can be used for both directionality identification and also identification of the
presence of the plate. A camera based panel is positioned on the ground which
can recognize the plate. For this purpose, a template image of the cross is used
and compared with the captured image for such identification. The camera has a
frame rate of 15 frames per second and by this, the plate can be identified on a
moving torpedo also. Hence it is very advantageous to use such a modified
image processing technique for torpedo tracking.
The system is based on a Correlation search methodology in which the template
images are searched in base images at a particular scale. If the right templates
are found, then calculations are done with the Indexes to find out whether the
template images are found at the particular position. If presence of the plate is
confirmed, then the equivalent decimal value is computed.
Accordingly, there is provided a method for automatic tracking of torpedo ladles
for hot metal logistics adapting an image processing techniques. For the purpose

of tracking the location of the torpedoes, a binary encoded plate is placed on the
torpedoes which contain slots. These slots represent the binary l's and O's which
are used to identify the torpedoes. Thus, each torpedo has a unique
identification number. This process of having binary digits on a plate is known as
binary encoding on the plate. Since, the plates constitute solid iron plates,
disturbances in the tracking process due to harsh environmental conditions or
dust and dirt accumulation, can be eliminated. An Image processing algorithm
based on cross correlation search methodology is developed and applied for
searching and identifying the plates in the images captured by a CCD camera.
The cross correlation of search methodology in general explains a measure of
similarity of two wave forms as a functions of a time-tag applied to one of them.
This is also known as a sliding dot product or inner product. It is commonly used
to search a Long-duration signal for a shorter, known feature. Thus, the
torpedoes can be identified by the unique numbers by which the plates can be
identified. Furthermore, a plurality of cameras when placed at a number of
locations, around the plant, then the complete cycle of a torpedo for logistical
purposes can be determined and the captured data can be used for further
analysis.
Image Processing technique of the invention is more advantageous to prior art
technique of using Radio frequency (RF) methods of hot metal logistics.
Thus, an application of the modified image processing technique to hot metal
logistics according to the invention proves to be quite advantageous in terms of

the environmental conditions present in the plant and also reduces the recurring
cost which is the major disadvantage of prior art technique such as RF tags.
Image processing algorithms are fast, accurate and easily implementable thereby
making the complete system fool proof.
Thus, this application of image processing to hot metal logistics proves to be
very effective in terms of the environmental conditions present in the plant and
also to reduces the recurring cost which is the major disadvantage with prior
work such as RF tags.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure - 1 - shows a schematic diagram of a plate depicting the identification
crosses and its binary encoding based on the slots present according to the
invention.
Figure - 2 - a pictorial view of a binary encoded plate used for tracking
according to the invention.
Figure - 3 - a pictorial view of a template image used to identify the plate
Figure - 4 - a schematic diagram illustrating the process of the invention.
DETAIL DESCRIPTION OF THE INVENTION
As shown in figure - 1, the torpedo ladles contain slots, and a binary-encoded
plate including identification crosses placed on the slots.

In figure 1, a detailed descriptive drawing of the plate is given. There are at least
three crosses present in the plate which provide the identification of the plate.
The distances of the crosses play a very vital role in the identification of that
pattern. The two crosses on one side and the third cross on the other side is
used to provide the direction of the movement of the plates. The binary
encoding is done based on the slots which are of different color than that of the
plate. Hence, if slots are present at a particular position, it represents a binary 1
and the absence of the slot represents a binary 0.
Figure - 2 shows a picture showing the binary encoded plate used for tracking
the ladles.
Figure - 3 shows an image captured by a CCD camera of the binary coded plates
fixed on the torpedo vessel.
In figure 4, a detailed descriptive drawing of a process adapted in the torpedo
tracking methodology is presented. The method comprises the steps of placing a
plurality of binary encoded plates on the slots configured on the torpedo vessel
which are then captured by a CCD camera. The images thus captured are then
sent to a computer device which contains an image processing algorithm that is
used to decode the decimal number from the binary encoded plate. Once the
step of decoding is completed, the data from the computer device is sent to a
central server where the data is stored over a period of time. Hence, this data is
used for torpedo tracking and in turn also providing complete hot metal logistics.

WE CLAIM
1. A method for automatic tracking of the movement of torpedo ladles
carrying hot metal in a steel plant, the method comprising the steps of:
- providing a plate corresponding to at least one slot configured on a
torpedo vessel, the plate being assigned with identification marks in the
form of crosses and a space between the crosses allotted with encoded
binary numbers in the form of slots, the slots representing the binary 1's
and O's which identify the torpedo vessel;
- providing at least one CCD camera capturing the image of the plates
disposed on the torpedo;
- transmitting the captured image from the camera to a computer device
incorporated with an image processing algorithm enabling decoding the
binary code to a decimal number; and
- transmitting the decoded data from the computer device to a central
server for storage and tracking of torpedo vessel movement.
2. The method as claimed in claim 1, wherein the image processing
algorithm is based on correlation search methodology in which the
template images are searched in the base image at a particular scale.

3. The method as claimed in claim 1 or 2, wherein when a right template is
identified through search, next calculation is made with the indexes to find
out whether the template image was detected at the particular location.
4. The method as claimed in claims 1 to 3, wherein the equivalent decimal
value is computed once the presence of the location of the binary-
encoded plate is confirmed.
5. A method for automatic tracking of the movement of torpedo ladles
carrying hot metal in a steel plant, as substantially described and
illustrated herein with reference to the accompanying drawings.

The invention relates to a method for automatic tracking of torpedo ladles for hot metal logistics adapting an image processing techniques. For the purpose of tracking the location of the torpedoes, a binary encoded plate is placed on the torpedoes which contain slots. These slots represent the binary 1's and O's which are used to identify the torpedoes. Thus, each torpedo has a unique identification number. This process of having binary digits on a plate is known as binary encoding on the plate. Since, the plates constitute solid iron plates, disturbances in the tracking process due to harsh environmental conditions or dust and dirt accumulation, can be eliminated. An Image processing algorithm based on cross correlation search methodology is developed and applied for
searching and identifying the plates in the images captured by a CCD camera. Thus, the torpedoes can be identified by the unique numbers by which the plates can be identified.