DESC:FORM – 2

THE PATENTS ACT, 1970
(39 of 1970)

COMPLETE SPECIFICATION
(See section 10; rule 13)

“AUTO GANTRY POSITIONING OF RTG CRANE"

Adani Ports and Special Economic Zone Limited
A Company Incorporated under the Indian Companies Act
Adani House, Near Mithakhali Circle,
Navrangpura, Ahmedabad Gujarat India380009

The following specification particularly describes the nature of this invention:
FIELD OF INVENTION:

The present invention relates to Auto Gantry positioning of RTG crane. More particularly, the present invention relates to an Auto Gantry Positioning of RTG Crane whereby the RTG Crane (Rubber Tyre Gantry) moves to the designated bay in the Container Terminal yard, at which job is to be done, automatically; wherein said job is to load and unload the containers.
BACKGROUND OF INVENTION:
A rubber tyre gantry crane (RTG crane) (also transtainer) is a mobile gantry crane used in intermodal operations to ground or stack containers. Inbound containers are stored for future pickup by drayage trucks, and outbound are stored for future loading on to vessels. RTGs typically straddle multiple lanes, with one lane reserved for container transfers. Said Rubber Tyre Gantry (RTG) Crane is used in the container yards (Y) for the handling i.e. loading (L) and unloading (UL) of containers in the container stack (CS). Container Yard (Y) receives containers from ships in the yards usually with import cargo or for transhipment to other containers terminal or empty.
Being mobile, RTGs are often powered by Diesel generator systems (gensets) of 100 to 600kW. The first electrified rubber-typed gantry cranes (ERTG) in the China was unveiled in Aug 2008by The She Kou container terminal (SCT). The new technology reduces fuel consumption by an estimated 95 percent.

Typical RTGs comprises of:
• the vertical girders
• two horizontal girders mounted on said vertical girders,
• spreader
• hoist
• trolley

said vertical girders are in pair on each side, travelling on the track using tyres below vertical girders;

said spreader attached to the hoist, mounted on the trolley, and is used to unload containers from truck to stack and load containers on truck from stack for the movement outside the terminal

said structure achieves the task by travelling on the horizontal girder over the containers stack.

All the movements (Trolley- forward and backward, Hoist up and down and spreader forward and reverse) in a conventional RTG (Rubber Tyre Gantry) Crane is done by the operator sitting in the cabin at a height of 18.1 meter above the ground or sitting in a Remote Operations Station, if Crane is remotely operated.

Said RTG Crane is used in the container terminals or yards for the handling i.e. loading and unloading of containers in or from the stack. Container Terminals receive containers from Ships in the yards usually with import cargo or for transhipment to other containers terminal or empty.

Similarly, container terminal also receive loaded or empty containers for movement on to the ships. Here RTG (Rubber Tyre Gantry) Crane unloads the containers from Truck in the stack and further loads them on trucks for the movement on quay.

In a container terminal, containers are stacked in the yard, before being sent to the ship or outside container terminal. This stacking of the containers in the container yards is done by the RTG (Rubber Tyre Gantry) crane that travels on wheels over the stack of containers.
Containers movement from ship to the shore is handled by Quay Cranes and containers are transported to container yard (Y) by Trucks (TR). In yard (Y), Rubber Tyre Gantry Cranes (RTG), having two horizontal girders (HG) mounted on the vertical girders (VG), two on each side, travelling on the track using tyres below vertical girders (VG), is used to unload (UL) containers from truck (TR) in stack and load (L) containers on truck (TR) for the movement outside the terminal with the help of spreader (S) attached to the Hoist (H) mounted on the trolley (T), travelling on the horizontal girder (HG) over the containers stack (CS).
Similarly, container terminal also receives loaded or empty containers for movement on to the ships. Here Rubber Tyre Gantry (RTG) Crane unloads (UL) the containers from truck (TR) in the stack and further loads (L) them on trucks (TR) for the movement on quay.
All the movements (Trolley (T)- forward and backward, Hoist (H) up and down and Crane forward and reverse) in a conventional Rubber Tyre Gantry (RTG) Crane is done by the operator sitting in the cabin (HE) of the RTG Crane or sitting in a Remote Operations Station, if crane is remotely operated.
The crane operator have a VMT (Vehicle Mounted Terminal) in his cabin, at which operator receives regular information of the jobs i.e. Loading or Unloading, to be performed.
During the loading of container from the Yard to the truck or unloading container from the truck in the yard, the operator of the RTG Crane have to move the RTG crane manually to the desired bay from which container is to be lift up or to be dropped. This manual movement of RTG crane requires operator to make many adjustments (Reverse and forward) to adjust the crane in accordance to the bay.
In a conventional RTG Crane, on receiving the job on VMT, crane operator starts the movement of the RTG crane to the designated bay. The operator has to be vigilant of the current location and destination bay number. This manual movement of RTG crane requires frequent forward and backward adjustment which requires time and thus affecting the Container Terminal productivity

PRIOR ART AND IT`S DISADVANTAGES:

• US9410804 B2 relates to techniques for positioning vehicles and movement of the Container Handling Devices using distance sensor. The invented system is for the cranes i.e. of Auto Gantry of the RTG crane, which uses the gantry encoders (GE) that converts the angular position or motion of a shaft or axle to an analogue or digital code and transfers same to the controller (C). Encoder is already available as standard feature of the RTG crane, thus there is no cost incurred on equipment. While the prior art is based on used of distance sensors that makes system costlier and need development of additional infrastructure such as distance sensor sensing plates installation. Also, in the prior art, the position of vehicle updated to the data processing centre with use of satellite for communication which increases dependency on satellite signalling & environmental conditions. The invented system of Auto Gantry of RTG crane, the communication is made with controller using wi-fi which is more reliable then satellite based communication system.

• EP0185816 A1 relates to a vehicle guidance and control system that discloses a vehicle guidance and control system has a number of trucks (10) whose movement is controlled by a base station. Each truck periodically fixes its own position in relation to marker boards (8) consisting of patterns of reflective coded stripes by scanning a narrow laser beam (14) in a predetermined direction across the stripes. Using at least two boards (8) its position can be determined by triangulation, and because the beam scans in a fixed direction, the positional accuracy can be determined by a particular stripe or edge of a stripe, and not by the size of a marker board as a whole.

• However, the said prior art fails to mobilize the rubber tyre gantry automatically. Said prior art uses positioning and guidance of container handling vehicles through laser sensors and reflectors. Also, the prior art fails to define the communication mechanism that is required to release command to the container handling devices. Further, The use of Laser sensors and reflectors in prior art increases the cost of the said system.

DISADVANTAGES OF PRIOR ART:

The conventional RTG crane involves manual intervention for the movement to the designated bay and suffers from following disadvantages:
1. It consumes a lot of time for the RTG crane operator to move the RTG crane to the designated bay, because he has to constantly look downwards for the bay number and traffic in the yard.
2. On reaching at the designated bay, the operator requires frequent forward and backward adjustments.
3. Conventional RTG crane need human intervention for the movement, thereby adding delay in the operations.
4. They are less efficient.
5. They are difficult to operate.
Thus, there is an unmet need to Auto Gantry Positioning of RTG Crane which automates the movement of RTG crane to the designated bay in the Container Terminal yard, at which job is to be done, automatically.

OBJECTS OF THE PRESENT INVENTION:
The main object of the present invention is to provide an Auto Gantry positioning system of RTG crane.
Yet another object of the present invention is to provide an Auto Gantry positioning System of RTG crane that consumes minimum time.
Yet another object of the present invention is to provide an Auto Gantry Positioning System of RTG crane that further eliminates the requirement of frequent forward and backward adjustments.
Yet another object of the present invention is to provide an Auto Gantry Positioning System of RTG crane that works automatically and eliminates the human intervention in the movement of the RTG crane.
Yet another object of the present invention is to provide an Auto Gantry Positioning System of RTG crane that eliminates the dependency of movement of RTG crane on RTG crane operator and thereby enhances the efficiency of port operations.
Yet another object of the present invention is to provide an Auto Gantry Positioning System of RTG crane that enhances overall Container Terminal efficiency and safety.
Yet another object of the present is to provide an Auto Gantry Positioning System of RTG crane that obviates the problems of the prior art.
BRIEF DESCRIPTION OF DRAWINGS:

FIGURE DESRIPTION
Fig. 1 : Shows Rubber tyre gantry crane of the present Auto Gantry Positioning System of RTG Crane.
Fig. 2 : Shows Block, Bay, Row, tire of the present Auto Gantry Positioning System of RTG Crane.
Fig. 3
: Shows the block diagram of the present Auto Gantry Positioning System of RTG Crane.
Fig. 4 : Shows the installation of proximity switches (PS) and reference plates (RP) in RTG crane of the present Auto Gantry Positioning System of RTG crane.
Fig. 5
: Shows enlarged view of installed proximity switches (PS) of Fig.4 of the present Auto Gantry Positioning System of RTG crane.
Fig. 6 : Shows enlarged view of installed reference plates (RP) of Fig.4 of the present Auto Gantry Positioning System of RTG Crane.
Fig. 7 : Shows installation of reflectors (ST) and photo sensors (RS) of the present Auto Gantry Positioning System of RTG crane.
Fig 8 : Shows the flow chart for unloading cycle of the present Auto Gantry Positioning System of RTG crane.

Meaning of Reference numerals of said format of drw said component parts of present Auto Gantry Positioning System of RTG crane.
(A) : Auto Gantry Positioning System of RTG crane
(RTG) : Rubber Tyre Gantry
(S) : Spreader
(TR) : Truck
(DT) : Drive In Trolley
(RP) : Reference Plate
(ST) : Reflectors
(BB) : Bus Bar
(T) : Trolley
(PS) : Proximity Switches
(CPS) : Means of sensing
(CRGE) : Means of correcting
(H) : Hoist and Hoist Encoder
(L) : Load
(UL) : Unload
(HE) : Hoist Encoder
(RS) : Photo sensors
(CPHS) : Means of Reflector sensing
(GE) : Gantry Encoder
(CRGC) : Means of comparison
(C) : Controller
(VMT) : Vehicle Mounted Terminal
(VD) : Means for display
(TI) : Tier
(BA) : Bay
(RO) : Row
(BL) : Block
(HD) : Hoist Drive
(HM) : Hoist Motor
(GD) : Gantry Drive
(GM) : Gantry Motor
(Y) : Yard
(CS) : Container Stack
(HG) : Horizontal Girder
(VG) : Vertical Girder
(GD) : Gantry Driver
(LS) : Laser Sensors

DETAILED DESCRIPTION OF INVENTION:

The present invention embodies an Auto Gantry Positioning System of RTG crane which ensures that the RTG Crane (Rubber Tyre Gantry) moves to the designated bay in the Container Terminal yard, at which job is to be done, automatically, automatically, without human intervention.
Present Auto Gantry positioning System of RTG crane (A) is installed in the existing infrastructure of the container terminal.
Referring to Fig. 1 to 8, The RTG crane used in the present Auto gantry positioning system of RTG crane (A) uses existing RTG with:
• the vertical girders (VG)
• two horizontal girders (HG) mounted on said vertical girders,
• spreader (S)
• hoist (H)
• trolley (T)
• Bus Bar (BB),
• Drive-In Trolley (DT),
• Encoders (GE, TE and H).

and requires installation of following: (refer fig.4,5,6)
• Reference Plates(RP),
• Proximity Switches (PS),
• Photo sensors (RS),
• Reflectors(ST);

Wherein;
Containers in a container terminal are stacked in the yard, prior to shipping outside the said container terminal. Said stacking of the containers in the container yards is done by the Rubber Tyre Gantry (RTG) crane that travels on wheels over the container stack (CS). Said Rubber Tyre Gantry (RTG) crane operator seats in the operator cabin (HE) of Rubber Tyre Gantry (RTG) Crane, at a height of 18.1 meter from ground, to operate the crane. The crane operator has a Vehicle Mounted Terminal (VMT) in his cabin (HE).

A Vehicle Mounted Terminal (VMT) is a mobile electronic device having a Display, a keypad and a means for data transmission, at which operator receives regular information of the jobs wherein said job includes the container number and their location in the yard. Also if the said Rubber Tyre Gantry (RTG) is remotely operated, the operator seats in the remote operations station where he has the access of Rubber Tyre Gantry (RTG) through Wi-Fi network and job information through Vehicle Mounted Terminal (VMT).

Referring to fig. 1 to 8 present an Auto Gantry Positioning system of RTG crane (A) mainly comprises of a Rubber Tyre Gantry (RTG) crane further comprising:

• Proximity Switches (PS)
• Gantry Encoder (GE)
• Hoist Encoder (H)
• Photo Sensors (RS)
• Controller (C)
• Vehicle Mounted Terminal (VMT)
Wherein;
said Vehicle Mounted Terminal (VMT) is further comprised of:
? Means for display (VD), and

Said Vehicle Mounted Terminal (VMT) is a mobile electronic device having a means of Display (VD), a keypad and a means of transmitting (VT) of data transmission. The user or Rubber Tyre Gantry (RTG) Crane operator receives the visuals on the display of the container number on which either a loading (L) or unloading (UL) job is to be performed. Upon completion of the job the Rubber Tyre Gantry (RTG) Crane operator punches in the completion status and container position using keypad.
Said Gantry Encoder (GE) is installed with shaft of the RTG crane (RTG); wherein gantry encoder (GE) starts working as early as the command to move the RTG crane is transmitted by the operator. Said command is transmitted first to the Gantry Drive (GD), then to the Gantry Motor (GM) and thereby making RTG crane move. As the gantry encoder (GE) is installed on the shaft of the RTG crane, it starts converting the motion of a shaft to digital code and transfers same to the controller (C);
An encoder is an electro-mechanical device that converts the angular position or motion of a shaft or axle to an analogue or digital code and transfers same to the controller (C).

Said bus bar (BB) is a physical structure that supplies electricity to the Rubber Tyre Gantry (RTG) Crane. Each yard (Y) of a container terminal have bus bar (BB) structure installed across its length. The Drive In trolley (DT) of RTG crane gets attached to this bus bar (BB), whenever RTG crane enters yard (Y). Said Reference Plates (RP) are installed on said bus bar (BB) for providing reference to the Proximity Switches (PS).

Said proximity switch (PS) is provided for the purpose of detecting the presence of the nearby object without any physical contact. This absence of physical contact between proximity switch (PS) and sensed object adds to the life and reliability of the proximity switch (PS). Also a proximity switch (PS) does not detect any foreign object apart from metal, thus making it more reliable and thereby making the invention more reliable. Said proximity switch (PS) are in plurality in present system, enabling better detection of objects. Two proximity switches are installed on the drive trolley (DT) as shown in fig.4 and fig.5 of the RTG crane of the RTG crane and further the reference plates (RP) are installed in the yard on the Bus Bar structure, as shown in fig 4 and fig 6. Further, the inputs of said Proximity Switches (PS) is transmitted to the controller (C), which in accordance to the pre-defined matrix over writes the input of the Gantry Encoder (GE), thereby rectifying the position of the RTG crane.

Said bus bar (BB) have reflectors (ST) fixed on the top, across the yard to ensure that the RTG crane stops at the center of the said target bay; as shown in Fig.7. To read said reflectors a Photo Sensor (RS) is installed on the Drive-In Trolley (DT). Said RTG crane continues to move even after reaching to the designated bay until the reflector (ST) is read by the photo sensor (RS). Once the photo sensor (RS) senses the reflector (ST) the RTG crane stops movement, therefore ensuring that said RTG cranes stops at the center of the bay.

Said Controller (C) is a pre-programmed hardware which receives the inputs, processes the same and then gives the output. Said controller (C) receives the inputs from Proximity Switch (PS), Gantry Encoder (GE). Said controller (C) generates address of the RTG crane position based on the above inputs and it further comprises of:
? Means of comparison (CRGC)
? Means of reflector sensing (CPHS)
? Means of sensing (CPS)
? Means of correcting (CRGE)

Means of Comparison (CRGC): Means for comparison (CRGC) makes RTG crane (RTG) move towards the destination bay by taking input from the gantry encoder (GE). Means for comparison (CRGC) of said Gantry Encoder (GE) enables the movement of the RTG crane (RTG) towards correct target location from the current location.
Means of Sensing (CPS): As the RTG crane moves across the yards, the gantry encoder (GE) passes some unproductive moves to the controller (C), thereby effecting controller (C) performance in detecting the correct position of the RTG crane. In order to replace the unproductive inputs of gantry encoder (GE), Proximity switch 7 (PS) and proximity switch 8 (PS) are installed on the Drive-In trolley of the RTG crane. These Proximity Switches (PS) senses by the reference plates (RP) installed at bus bar structure on a pre-defined bay number using Means of sensing.
Means of correcting (CRGE): Means of correcting (CRGE) of said controller (C) enables the controller (C) to over write the inputs of the gantry encoder (GE) with the correct location of the RTG crane, based in the inputs of Proximity Switches (PS). This correction is done using Means of sensing (CPS) whereby the proximity switches (PS) senses the reference plates and detects the correct pre-defined position of the RTG crane.
Means of Reflector Sensing (CPHS): In order to ensure that the RTG crane is stopped at the center of the target bay, the bus bar (BB) structure is fitted with reflectors (ST) across the yard, parallel to each bay. To read these reflectors a Photo Sensor (RS) has been fitted on the Drive-In Trolley (DT). RTG crane continue to move even after reaching to the designated bay until the reflector (ST) is read by the photo sensor (RS). Once the photo sensor (RS) senses the reflector (ST), same is transmitted to the controller (C), controller (C) then sends the stop command to the Gantry Drive (GD). The Gantry Drive (GD) guides the gantry motor (GM) to stop the RTG crane movement.
Referring to fig.3 said Controller (C) receives the inputs from the encoder (GE) through Gantry Drive (GE) and Gantry Motor (GM) when RTG crane moves. Based on the last input received from the Gantry encoder (GE) and the target bay number received, the controller (C) computes the distance required to travel by the RTG crane. Said computation is done through the inputs of the Gantry Encoder (GE), that is installed in the shaft of the RTG crane, which converts the angular motion of shaft to an analogue or digital code and transfers same to the controller (C).
Thus, when the current position of the RTG crane becomes equal to the target position, RTG crane stops and the Bay number are captured.

WORKING OF INVENTION:
An unloading (UL) cycle for the detailed explanation on the stepwise working of the invention is provided below, referring to the numerals given in the flow chart illustrated in Fig: 8.
• 1 & 2- The unloading (UL) process starts with Truck (TR) carrying container arrives at the Pre Gate of the Port.
• 3, 4 & 5 - Upon its arrival a gate entry operator checks the shipping documents and allows the movement of the truck inside the terminal; if the shipping documents meet standards else truck (TR) is directed towards buffer yard to unload (UL) the container.
• 6, 7 & 8- On arrival of the truck (TR), carrying container, at the terminal gate position is generated by the gate operator. Said position is given to the truck driver and is simultaneously displayed on the VMT of the RTG crane.
• 9- Controller (C) receives the target position at which job is to be performed and compares it with the current position.
• 10- Controller (C) receives the inputs from the Gantry Encoder (GE) and makes RTG Crane move towards the target position.
• 11- Controller (C) receives the input from the proximity switches and over-write the input received from the Gantry encoder (GE), thereby rectifying the position of the RTG crane.
• 12 & 13- Controller (C) compares the current position of the RTG crane with Target Position, based on the inputs received from Gantry Encoder (GE) and allows the movement of the RTG crane till both Target and Current Position become equal.
• 13 & 14- When both current position and the target position of the RTG crane becomes equal the controller checks for the input of the photo sensor (RS) in order to ensure the RTG crane is aligned to the centre of the bay. Once the photo sensor (RS) senses the reflector (ST) controller stops the movement of RTG crane by giving command to the Gantry Motor (GM) through Gantry Drive (GD).
• 15- The movement of the RTG stops and the Controller (C) records the stop position of the RTG crane for future reference.
,CLAIMS:We Claim:
1. Present an Auto Gantry Positioning system for RTG crane (A) mainly comprises of a Rubber Tyre Gantry (RTG) crane further comprising of:
• Proximity Switches (PS),
• Gantry Encoder (GE),
• Controller (C),
• Vehicle Mounted Terminal (VMT),
• the vertical girders (VG),
• two horizontal girders (HG) mounted on said vertical girders,
• spreader (S),
• hoist (H),
• trolley (T),
• Bus Bar (BB),
• Drive-In Trolley (DT),
• Encoders (GE, TE and H),
• Reference Plates (RP),
• Photo sensors (RS),
• Reflectors (ST);

wherein:
- said controller (C) further comprises of:
? Means of comparison (CRGC),
? Means of reflector sensing (CPHS),
? Means of sensing (CPS),
? Means of correcting (CRGE);
- said Vehicle Mounted Terminal (VMT) is further comprised of:
? Means for display (VD), and
- said photo sensors (RS) is further comprises of:
? Means of reflector sensing (CPHS);

said Vehicle Mounted Terminal (VMT) is a mobile electronic device having a means of Display (VD), a keypad and a means of transmitting (VT) of data transmission wherein the user or Rubber Tyre Gantry (RTG) Crane operator receives the visuals on the display of the container number on which either a loading (L) or unloading (UL) job is performed and their location;

said proximity switch (PS) is provided for the purpose of detecting the presence of the nearby object without any physical contact where in absence of physical contact between proximity switch (PS) and sensed object adds to the life and reliability of the proximity switch (PS), also a proximity switch (PS) does not detect any foreign object apart from metal, and thereby making the invention more reliable; said proximity switch (PS) are in plurality in present system, enabling better detection of objects, wherein two proximity switches are installed on the drive trolley (DT) as shown in fig.4 and fig.5 of the RTG crane and further the reference plates (RP) are installed in the yard on the Bus Bar structure, as shown in fig 4 and fig 6, further, the inputs of said Proximity Switches (PS) is transmitted to the controller (C), which in accordance to the pre-defined matrix over writes the input of the Gantry Encoder (GE), thereby rectifying the position of the RTG crane;

said Gantry Encoder (GE) is installed with shaft of the RTG crane (RTG); wherein gantry encoder (GE) starts working only when the command is passed by the RTG crane operator to move the RTG crane and said command is transmitted first to the Gantry Drive (GD), then to the Gantry Motor (GM) whereby the RTG crane starts moving with the movement of the Gantry Motor (GM); the gantry encoder (GE)is installed on the shaft of the RTG crane, and starts converting the motion of a shaft to digital code and transfer same to the controller (C);

an encoder , is an electro-mechanical device that converts the angular position or motion of a shaft or axle to an analogue or digital code and transfers same to the controller (C); said controller is a pre-programmed hard ware which receives the inputs, processes the same and then gives the output;

said bus bar (BB) is a physical structure that supplies electricity to the Rubber Tyre Gantry (RTG) Crane wherein each yard (Y) of a container terminal have bus bar (BB) structure installed across its length; said Drive In trolley (DT) of RTG crane gets attached to the bus bar (BB), whenever RTG crane enters yard (Y); said Reference Plates (RP) are installed on said bus bar (BB) for providing reference to the Laser Sensor (LS) and Proximity Switches (PS); said Laser Sensor (LS) and Proximity Switches (PS) are installed on said Drive-In Trolley (DT) as shown in Fig.4 and Fig.5; said bus bar (BB) is attached with the reflectors (ST) across the yard to ensure that the RTG crane stops at the centre of the said target bay; as shown in Fig.7, further to read said reflectors a Photo Sensor (RS) is attached to the Drive-In Trolley (DT), wherein said RTG crane continue to move even after reaching to the designated bay until the reflector (ST) is read by the photo sensor (RS); the photo sensor (RS) senses the reflector (ST) the RTG crane stops movement, therefore ensures that said RTG cranes stops at the centre of the bay;

said Controller (C) processes the inputs to it, for generating the container position address; said controller receives the inputs from Laser Sensor (LS), Proximity Switch (PS), Gantry Encoder (GE), Trolley Encoder (TE), and Hoist Encoder (H); said controller (C) generates container position address which is a combination of: Yard (Y) Number, Block Number, Bay Number, Row Number and Tier Number; said controller (C) further comprises of:

Means of Comparison (CRGC): Means for comparison (CRGC) makes RTG crane (RTG) move towards the destination bay by taking input from the gantry encoder (GE); Means for comparison (CRGC) of said Gantry Encoder (GE) enables the movement of the RTG crane (RTG) towards correct target location from the current location;
Means of Sensing (CPS): As the RTG crane moves across the yards, the gantry encoder (GE) passes some unproductive moves to the controller (C), thereby effecting controller (C) performance in detecting the correct position of the RTG crane; in order to replace the unproductive inputs of gantry encoder (GE), Proximity switch 7 (PS) and proximity switch 8 (PS) are installed on the Drive-In trolley of the RTG crane; said Proximity Switches (PS) senses by the reference plates (RP) installed at bus bar structure on a pre-defined bay number using Means of sensing;
Means of correcting (CRGE): Means of correcting (CRGE) of said controller (C) enables the controller (C) to over write the inputs of the gantry encoder (GE) with the correct location of the RTG crane, based in the inputs of Proximity Switches (PS), said correction is done using Means of sensing (CPS) whereby the proximity switches (PS) senses the reference plates and detects the correct pre-defined position of the RTG crane;
Means of Reflector Sensing (CPHS): In order to ensure that the RTG crane is stopped at the centre of the target bay, the bus bar (BB) structure is fitted with reflectors (ST) across the yard, parallel to each bay; to read these reflectors a Photo Sensor (RS) has been fitted on the Drive-In Trolley (DT); RTG crane continue to move even after reaching to the designated bay until the reflector (ST) is read by the photo sensor (RS); Once the photo sensor (RS) senses the reflector (ST), same is transmitted to the controller (C), controller (C) then sends the stop command to the Gantry Drive (GD); the Gantry Drive (GD) guides the gantry motor (GM) to stop the RTG crane movement;

said Controller (C) receives the inputs from the encoder (GE) through Gantry Drive (GE) and Gantry Motor (GM) when RTG crane moves, based on the last input received from the Gantry encoder (GE) and the target bay number received, the controller (C) computes the distance required to travel by the RTG crane; said computation is done through the inputs of the Gantry Encoder (GE), that is installed in the shaft of the RTG crane, which converts the angular motion of shaft to an analogue or digital code and transfers same to the controller (C).

2. Present Auto Gantry Positioning system for RTG crane (A) as claimed in claim 1, wherein said plurality of proximity switches (PS), are installed on the drive in trolley of said RTG crane, to rectify the inputs of the gantry encoder (GE) to the controller (C).

3. Present Auto Gantry Positioning system for RTG crane (A) as claimed in claim 1 and 2, wherein said container Yard (Y) having reference plates (RP) is installed on the bus bar (BB) structure to be sensed by the Proximity Switches (PS).

Dated this 5th day of June 2017.

________________________
GOPI J. TRIVEDI (Ms.)
(Authorized Patent Agent of the Applicant)