CLIAMS:1. A system for coke oven identification & car tracking comprising of:
a wireless based communication systems for coke ovens at Pusher Side, Coke side and Quenching Side;
a cross battery interlocking mechanism;
an unique combination of Long Range RFID with active tag readers; and
a PLC, PC Hardware system, Radio Modem, RS232/RS485 Converters, Panel View operator Station, Omni Directional Antenna, VOIP (Voice on Internet Protocol) based telephone and a Gateway installed at a central station.

2. The system as claimed in claim 1, wherein, the long range RFID’s are installed at Pusher Side, Coke Side and Quenching Side with Readers at 2 Pusher Cars, 2 Guide Cars and 1 Quenching Car.

3. The system as claimed in claim 1, wherein, the RFID active tags are installed at each side of Pushing, Coking and Quenching and at strategic Locations for enabling 3 operations of Door opening, Pushing and leveling with a single oven ID tag.

4. The system as claimed in claim 1, wherein, the installation of RFID active tags is carried out beneath the walkway for Coke Side with mirror imaged Guide Cars in operation.

5. The system as claimed in claim 1, wherein, the Main PLC, PC and Radio Modems with splitters and Yagi antennas are located at Central Coal Tower Location.

6. The system as claimed in claim 1, wherein, the cross battery interlocking mechanism comprises an 82 bits long alphanumeric character, which is generated whenever any car reader falls in view of any tag.

7. The system as claimed in claim 6, wherein the alphanumeric character is generated digitally by the combination of Guide Car and the Quenching Car, and it does not consider the oven number.

8. The system as claimed in claim 6, wherein the CBI mechanism is generated by the combination of scheduled oven (optional), the existing digital CBI signal and position of all cars in the quenching car.

9. The system as claimed in claim 6, wherein, the middle 4 letters of the alphanumeric character is filtered and read by the Car PLC through ASCII read at Serial Port and passed on to the Central Coal Tower Main PLC through wireless communication.

10. The system as claimed in claim 6, wherein, the CBI mechanism further comprises of a truth table for each oven, at each side, which detects the oven number at which a particular car is located.

11. The system as claimed in any of the preceding claims wherein, the Car Position and Car Operation at each side are displayed at all operator stations (panel view terminals) of each car.

12. The system as claimed in claim 11, wherein, the car operations includes Door opening OR Pushing OR Leveling OR Traveling L/R and are detected based upon combination of the digital signals detected at Car.

13. The system as claimed in claim 11, wherein, the operations for Pusher Car includes Door Opening, Left / Right movement, Pushing – Forward / Backward, Leveling – Forward / Backward; for Door Extractor (Guide Car) – Guide alignment, Door open, Permission to Push; for Quenching Car – Permission to Push.

Dated: this 29th day of September, 2014.
,TagSPECI:A SYSTEM FOR COKE OVEN IDENTIFICATION & CAR TRACKING

FIELD OF INVENTION

The present invention relates to an improved system for identification, tracking and radio communication for coke ovens at Pusher side, Coke side and Quenching Side. More particularly, the present invention relates to a wireless communication system including integrated oven identification, car tracking and cross battery interlocking system for efficiently controlling every movement of the car.

BACKGROUND ART

Goods shipped from a manufacturing plant, warehouse or port entry, to a destination are normally racked to assure their timely and safe delivery. Tracking has heretofore been accomplished in part by use of shipping documents and negotiable instruments, some of which travel with the goods and others of which are transmitted by post or courier to a receiving destination. The disclosure provides a record which is completed only on the safe delivery and acceptance of the goods; however, during transit, there sometimes is a need to know the location of the goods. Knowledge of the location of the goods is used for inventory control, scheduling and monitoring.

Most present-day tracking systems are land-based systems wherein a radio unit on the article transmits information to wayside stations of a fixed network, such as the public land mobile radio network or a cellular network. These networks do not have ubiquitous coverage, and those tracking units are expensive.

Further in prior art, in an asset tracking system disclosed in U.S. application Serial No. 08/484,750 entitled "Local Communication Network for Power Reduction and Enhanced Reliability in a Multiple Node Tracking System" by Welles et al. and in U.S. application Serial No. 08/487,272 entitled "Protocol and Mechanism for Primary and Mutter Mode Communication for Asset Tracking" by Ali et al. One mode is communication between the central station and the tracking units, which is usually via wireless. The second mode is a local area network, referred to as the "mutter" mode, between tracking units. One of the tracking units, denoted the master unit, communicates with the central station.
Radio technology has long been used to support wireless communications. Based on the evolution of radio technology over the years, it is now possible to communicate via Radio Frequency (RF) in many different ways. For example, according to current RFID technology, it is possible for a so-called RFID tag reader to communicate with multiple RFID tags in a monitored region. According to another technology such as Bluetooth, it is possible for a computer to implement short-range communications with devices such as cell phones, keyboards, etc. According to yet another technology such as WiFi, it is possible to implement a wireless access point in a home network to support medium range communications between the wireless access point and devices such as computers, televisions, etc.

Certain RFID technology enables RFID tag readers to communicate with passive RFID tags. For example, to support communications with the passive RFID tag reader systems, a tag reader's transmitter and receiver must be simultaneously active. In general, this is because the tag reader's transmitted signal is used to power the tag while the tag, in turn, generates a reply back to the tag reader. If the tag reader does not output an RF signal while listening for a tag's response, the tag reader would not be able to receive data from the tag because the tag will power down, making it unable to respond. Thus, for passive tags, the tag reader must output RF energy during the tag's responses to the reader's commands. Radio technologies such as WiFi, bluetooth, cellular phones, etc., support communications in a different way than do passive RFID tag readers.

RFID technology is conventionally used to locate the position or movement of tagged objects. In some embodiments, RFID implementations for detection assume that tagged objects are or will come within range of a RFID reader or detection devices, which may not be easily controlled or ascertained. In some implementations, over-design (e.g., larger density of readers or wider scan zone) can ensure better coverage to enable detection. In some other embodiments, a priori knowledge defines the interaction zone between RFID devices, reducing opportunities for human interaction. Applying RFID technology in unconventional ways may open up new opportunities for interactive applications.

Other Prior Art in Oven Identification System (OIS)

Since the late eighties, different types of OIS have been invented time to time. With the advent of wireless communication technology, OIS have made great strides. Some of the old OIS techniques are mentioned below:

• Infrared transmitters and receivers:

Infrared transmitters (generally 4 or 5 as a set) are mounted in the car and infrared receivers are mounted under each oven. During receiver mounting, careful alignment is made to endure the transmitter and the receiver axis is in the same vertical plane. The transmitters are powered only when the pusher operates to eliminate detection while movement.

Advantages of this system:
• Free from communication hazards (No Radio modem required)
• Easy field testing with a portable transmitter set
• Direct hardwared connection to PLC

Disadvantages of this system:
• Huge Cabling
• Difficult to maintain so many sensors
• Dust shall jeopardize detection
• Difficult to detect while in motion
• Alignment problems with track up / down
• Only can be mounted practically for the Pusher side and the quenching side

Today, with the advent of good and reliable communication technology these sensors are seldom used.

• Slotted Hole plates and C-frame head comprising through beam sensors

Slotted hole plates coded in 8421 binary pattern are mounted below each oven. The plate has holes on say the 1st, 2nd, 3rd and the 5th places from the Least Significant Bit (LSB) side, adding the weightages of 1,2,4 and 16 respectively, the total becomes 23, the oven no. is 523. The 2 transmitters below the line of 8 are provided for auto positioning. The plate width is such that these 2 receivers must get cut-off when the car is aligned to that oven. This gives the confirmation of exact positioning.
Once the oven number is detected, it is sent to the central control room through wireless radio communication.

Advantages of this system:
• No cabling required at the stationary side
• No maintenance required for metal plates
• Positioning also done
• Less threat from dust
• For track up /down slots there to adjust

Disadvantages of this system:
• Often plates are mechanically damaged due to misalignment (guide car & quenching car side)
• Free from communication hazards (No Radio modem required)
• Difficult to detect while in motion
• Communication dependent
• Equipment difficult to maintain at guide car & quenching car side

SUMMARY OF INVENTION

The shortcomings of the prior art are overcome and additional advantages are provided through the provision of an OIS and communication network constructed in accordance with an exemplary embodiment of the present invention.

Therefore such as herein described there is provided a system for coke oven identification & car tracking comprising of: a wireless based communication systems for coke ovens at Pusher Side, Coke side and Quenching Side, a cross battery interlocking mechanism, an unique combination of Long Range RFID with active tag readers, a PLC, PC Hardware system, Radio Modem, RS232/RS485 Converter, Panel View operator Station, Omni Directional Antenna, VOIP (Voice on Internet Protocol) based telephone and a Gateway installed in all cars.

As per another object of the present invention, the said long range RFID’s are installed at Pusher Side, Coke Side and Quenching Side with Readers at 2 Pusher Cars, 2 Guide Cars and 1 Quenching Car.

As per another object of the present invention, the RFID active tags are installed at each side – Pushing, Coke and Quenching at strategic plurality of Locations for enabling 3 operations of Door opening, Pushing and leveling with a single oven ID tag.

As per another object of the present invention, the installation of RFID active tags is done beneath the walkway for Coke Side with mirror imaged Guide Cars in operation.

As per an exemplary embodiment of the present invention, there is provided an auto generated 82 bit long alphanumeric character, which is generated whenever any car reader falls in front of any tag.

As per yet another object of the present invention, the operations of Door opening OR Pushing OR Leveling OR Traveling L/R are detected based upon combination of the digital signals detected at Car. In addition the Car Position and Car Operation at each side are displayed at all operator stations (panel view terminals) of each car. The operations for Pusher Car includes Door Opening, Left / Right movement, Pushing – Forward / Backward, Leveling – Forward / Backward; for Door Extractor (Guide Car) – Guide alignment, Door open, Permission to Push; for Quenching Car – Permission to Push.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Fig. 1 illustrates Cross Battery Interlock Animation Demonstration in accordance with the present invention;

Fig. 2 illustrates 0 Cross Battery Interlock Mechanism in accordance with the present invention.

DETAILED DESCRIPTION

As in prior art, shippers have provided information on the location of goods by tracking their vehicles, knowing what goods are loaded on those cars. Various devices have been used to track such cars. In the present case, the cars includes tag readers mounted upon used to facilitate interrogation of each car as it passes a way station and supply the car's identification. This information is then transmitted to a central station which tracks the locations of cars.

The Oven Identification System (OIS) as disclosed herein is RFID based, which consists of a tag reader which is mounted in all moving cars. Tags for each oven are mounted in the Pushing, Quenching and Guide Car walkway side. All three operations of Pushing, Leveling, Traveling and Door opening are detected by the Oven Identification System. Thereby, the OIS generates the following quantities per oven: Pushing Time, Charging time, Actual Coking Period.

An 82 bit alphanumeric code is generated in the PLC by the unique RFID tag. Every Tag is factory programmed (since these are read-only tags). All 82 bits are not utilized for the application, since the unique code rests in between in 4 HEX letters. The length assigned in the PLC program for reading by the ASCII line read instruction through the serial port of the PLC is also 82; but then in the subsequent instruction in the PLC program the 4 letter HEX code is filtered and kept in proper place for all the 65 ovens. It may be noted that before placing a Tag it is ensured that all the 65536 combinations possible with 4 HEX letters have not been exhausted. Thus every oven responds one particular HEX code whenever the Pusher points to the oven. Same is for the Door Opening and the Leveling mechanisms.

As per an exemplary embodiment, there is provided an Cross Battery Interlock (CBI) mechanism by which any wrong pushing is eliminated in a coke oven battery. The existing cross battery interlock is generated digitally by the combination of Guide Car and the Quenching Car, but it does not consider the oven number. The CBI from the system is generated by the combination of scheduled oven (optional), the existing digital CBI signal and position of all cars in the quenching car.

The main advantage that the system delivers is that it provides a veritable oven identification system where not a single pushing is missed even in months. The sensors are not affected by the dust and ambient conditions are another strong point.

For the communication systems, an Orthogonal Frequency Division Multiplexing (OFDM) design with Line of sight communication at 2.4GHz was chosen. Accordingly, antenna positions in the stationary side, moving coke side and moving pusher side were ensured without any structural impediments. For the communication systems (S/w side), the choice was between messaging and configuring producer / consumer tags.

There are 2 Master Radios on two sides – ‘Pusher Radio’ and ‘Master Coke’. There are 2 Repeater Radios for ‘Pusher Radio’ Master and 3 Repeater Radios for ‘Master Coke’. Under Pusher Radio there are Pusher 6 and Pusher 7; and under Master Coke there are DE13, DE17 and Quenching car.

For the detection systems, the task force had deliberated upon Short range RFID systems, Long range RFID systems, Radar based systems, plate coded systems, bar coded systems etc. Out of these; weighing the pros and cons, the Long range RFID system was selected. The short range RFID had not worked successfully in Batteries 1 & 4 of RSP, Battery 5 of BSP etc.; whereas the Radar based systems were not cost effective and had not been established till date. The plate coded system proved to be mechanically fragile in Battery 5 of BSL. All of these lead to selection of Long Range RFID system which were hitherto not used anywhere for our like Coke Oven batteries in the world.

For the communication systems (H/w side), broadly the selection is made between two categories – Line of Sight (2.4 GHz) and Without Line of sight (433 MHz). Whereas all over SAIL Coke ovens the without Line of Sight communication was used. However, since for this category every year licensing and license fee was required; also since it was a slow communication, therefore consciously the decision was taken to opt for line of sight communication. Accordingly, antenna positions in the stationary side, moving coke side and moving pusher side were ensured without any structural impediments. For the communication systems (S/w side), the choice was between messaging and configuring producer / consumer tags. Both of them were incorporated and the reason for this has been described in the EXPERIMENTAL section.

Also the communication between the RFID reader and the PLC was seamless; in the sense that the RFID reader provided RS232 output, which was converted to RS485 by the ADAM module and this was interfaced to the Compact Logic processor of the moving car.

For the controller side, it was imperative to have the same family of processors in the central location and also in the moving cars due to much seamless communication amongst all PLC units. For this an apt combination of the powerful Control Logics and economic Compact Logics was used. Since both belonged to the same NetLinx family of Rockwell automation, there was seamless communication among the central and 5 moving units.

Another feature of the system has been the Voice on Internet Protocol (VOIP) system amongst the central control room and the five moving cars. In all the six nodes, each can have a noise free peer to peer communication with other nodes, though the plant possesses voice communication systems (walkie-talkies) etc.

Long range RFID systems coupled with ‘Orthogonal Frequency Division Multiplexing’ wireless systems is used for a comprehensive oven identification system at Pusher side, Coke side and Quenching side in COB#4, BSP, Bhilai. With more than 200 tags in these three sides working 100%, a cross battery interlocking system has been developed and implemented which allows Pushing of an oven, only if the Pusher Car, the Guide Car and the Quenching Car point to the same scheduled oven. Thus the system eliminates wrong pushing, which not only cause large production delays but also are a threat to safety of equipment and personnel.

i. A unique combination of Long range RFID system & an OFDM wireless System integrated with a PLC seamlessly to read a unique tag no. for oven identification
ii. All operations of the car namely Left / Right Traversing, Door Opening, Pushing and Leveling is tracked and monitored by a single tag.
iii. Pushing Amperage is measured in the car and transferred to Central main PLC with oven no stamping and date & time stamping
iv. Operators of all cars know where other cars are exactly located and which operation in those cars is being done.
v. A cross battery interlock system developed which ensures Pushing only and only if the 3 cars – Pusher, Guide and Quenching are standing in the same scheduled designated oven

Cross Battery Interlocking:
The cross battery interlock mechanism shall be operating on the following principles:
The final Permission to Push is generated by RDCIS system, which ensures that all car level interlocks have been adhered. For example, for the DE car, its cage guide must be in forward position in the next scheduled oven (linkage to scheduled oven is optional), also This cage forwarding signal is coupled with Operator’s acknowledgement. Finally with these two events the system checks the RFID oven no. of DE Car. Similarly, in the Quenching car, the LOCO operator must provide the signal, which is again coupled with Oven RFID no. When these cumulative signals from DE side and LOCO side are there then the system checks the Pusher RFID no. and when found finally gives the PERMISSION TO PUSH as shown in Fig. 1

1. Pushing Interlock bypass switch (MCB) shall be provided in the electric post of CP-6 & CP-7. Once the bypass MCB is switched ‘ON’, it will bypass the pushing interlock generated by RDCIS system and switch over to the conventional relay circuit interlock system. This has been shown in Fig. 2
2. Initially, it was developed that next scheduled oven number shall be the primary key with which all the 3 car positions shall align. However, now it has been delinked and the interlocking does not necessitate convergence to oven schedule number. At any stage, if the operation feels, the provision of inclusion of next scheduled oven can be restored.
3. All temporary bypassing of DE and LOCO shall be done from HMI screens. This pertains to car-specific bypassing; whereas for gross anomalies, the electrical BYPASS from the electrical post shall be done. Who shall have the privilege password, is to be defined by BSP.
4. Only the quenching car shall be exempted from changing oven nos. (Only towards the quenching tower); once the Pushing starts. If the same happens with DE, immediately Pushing shall stop.
5. In case P-6 and P-7; DE13 and DE16 are both operational in Battery 4, then the system shall re-include scheduled oven in the logic.
6. The DE walkway has to be clean for the system to work satisfactorily. For this BSP has deployed two sweeping mechanisms in DE 13 and DE 16.

As such it is imperative for the different components of the invention to work seamlessly under an integrated environment, for example the detection of the oven nos. are happening in the 5 different cars concomitantly. Subsequently in real time there is an instantaneous messaging to the Central Control Room from all 5 movable cars about not only the new ovens detected, but also the current operation which is being carried out. These individual informations are interwoven in the main PLC of the central control room and based on different logic, decision for cross battery interlock and other annunciations, animation screens etc. are taken. For example, one moving car at a single point of time can have many positions like Stand Still, Moving Right / Left, Door Opening, Pushing forward / Backward, Leveling, Guide opening/closing etc. Therefore the oven detection module and the operation detection module are superimposed for combined information for the Cross Battery Interlocking to operate.

Following is the step by step delineation of the entire logic:
1. The RFID reader in the moving car reads the tag Unique ID decides insitu the Oven No. (by the Moving Car PLC), detects the operation of the car and transmits them to Main PLC in the central Control room.
2. The central control room Main PLC constantly gets these information from the 5 moving cars and as per the logic checks the next oven to be pushed from the Scheduling Model and this oven becomes the Primary Key for the alignment module in cross battery interlock.
3. The next operation which is expected during normal operation is the door opening of the Pusher Oven (Next to Push in the schedule), since it is mandatory to open a door before pushing it. The system tracks this in the pusher side and similarly tracks the guide closing at the Door Extractor side.
4. Then it checks whether all the three cars have arrived in the same oven. If yes then it waits for the Quenching car operator to set a manual acknowledgement and once the system receives this, the Permission to Push is given by the System.

In the preceding specification, the invention has been described with reference to specific embodiments thereof. It will be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.