1. RFID Based Line Follower Robot Used as a Service Provider in Automated
Restaurant System
Arpit Gupte, Kartik Makadia, Debostuti Das, Deepesh Kumar Agarwal
Student, 4TH
Year, Department of Computer Science and Engineering
East West Institute of Technology (VTU)
Bangalore, Karnataka.
India
1
arpitgupte@gmail.com
2
kartik.makadia@gmail.com
3
das.debostuti@gmail.com
4
deepeshag23@gmail.com
Abstract-More people prefer to dine out nowadays and the food
and beverage industry has to revolutionize its way of serving
customers in order to remain sustainable to the growing
population. This research aims at designing an Automated Food
Delivery System to overcome this problem. The new proposed
system structure consists of color lines that are drawn on the
restaurant ground and they link all tables to the kitchen serving
as a guiding track; a robot that is in sync with the ordering
system will serve. When customers place their order through the
ordering system, the system will send the order to the kitchen.
Once the dish is prepared, a signal will be sent to the robot then
robot will then deliver it to the specific table and return to the
kitchen and send a feedback signal to the ordering system as a
confirmation of delivery. This system is yet to be popular in the
food and beverage industry and there are several technical
difficulties to be overcome. However, once the technical
difficulties can be overcome and improvements are made, the
automated food delivery system using a robot is a possible
solution to the issues faced by thousand of restaurant owners.
I. INTRODUCTION
MORE and more people prefer to dine out nowadays. This is true
especially for the working population. Take Mumbai, India as an
example, the number of working population as shown in Figure 1.1 may
reflect the number of people dining out during lunch hour daily.
Fig 1.1 Principal Statistics of Labor Force, India
The number is telling a fact that the food and beverage industry has to
revolutionize its way of serving customers in order to remain sustainable
to the growing population. Thus, restaurants have come out with many
creative, effective and user-friendly ways to serve and deliver food.
Currently, Food Ordering and Delivering Systems can be generally
classified as Conventional Waiter-Serving System, Self-Service Buffet
System, Pen-and-Paper Self-Ordering System, 'Kaiten' Conveyor Belt
System (US Patent 5419410-Delivery system) and Fast-Food Self-
Carrying System (US Patent 4245720 - Fast food restaurant). Bottleneck
was found in each of these systems as the number of customers increases
significantly. The Conventional Waiter-Serving System has a drawback
in hiring of good employees. As for the Conveyor Belt System
restaurants, a large and fixed area is needed which
Greatly reduces the seating area available in the restaurant. Thus, this
research aims at designing an Automated Food Delivery System to
overcome the above mentioned issues with the current systems.
II. BACKGROUND REVIEW
A. Hydraulic System for Serving Food
With the introduction of automatic food display and service systems a
sushi chef can serve a greater number of customers while providing fresh
sushi to customers as soon as the customers are seated. One such food
display discloses a continuous chain of small food carriages having the
shape of boats arranged in a watercourse. The bow of each boat is
physically attached to the stem of an adjacent boat via a chain or other
interconnecting member. Customers seated around the watercourse will
remove their food order from the boats as they pass by. The chef
monitors and replenishes empty boats with the appropriate variety of
sushi.
[IS]
B. Conveyor System for Drive-In Restaurant
A conveyor system for drive-in restaurants consists of a plurality of tray-
supporting carriages which are electrically driven to move along a track
system including rails from which they derive their power. This invention
relates to new and useful improvement in conveyor systems, especially
adapted for use in drive-in restaurants. The food ordered by passengers in
automobiles parked at designated stations is delivered automatically to
proper stations from the restaurant building on trays moved by the
conveyor. The trays are returned by the conveyor to the restaurant
building when the food has been consumed, and the trays may also be

2. used collecting the money in payment for the food. The requirement for
live waitresses or waiters, commonly known as "carhops,' is virtually
eliminated, permitting a great saving in salaries.
C. Automatic Dish Serving System
This invention relates to an automatic dish serving system
Capable of effectively serving dishes including food and drink to
customers at restaurant. This system provides an automatic dish serving
system comprising a supply centre for supplying dish such as food and
drink to a customer's seat to which the food and drink are served; a
carrier wagon travelling along a route between the supply centre and the
customer's seat; and a route guiding means for guiding the carrier wagon
as to take an appropriate route, wherein the customers' seat is provided
with a turntable for retaining the served dishes of food and drink, and
provided with an arrival portion to which the carrier wagon arrives; and
wherein the
Carrier wagon is provided with a transfer means for transferring the dish
articles between the turntable and the carrier wagon.
III. NEW PROPOSED SYSTEM STRUCTURE
The new proposed system structure as shown in Figure 3.1 consists of
color lines that are drawn on the restaurant ground and they link all tables
to the kitchen as guiding track; a robot that synchronized with the
ordering system to know which table to serve and which track to follow.
Fig 3.1 New Proposed System Structure
When customers place their order though the ordering system; the system
will send the order to the kitchen. Once the dish is prepared, a signal will
be sent to the robot while the chef places those dish on the tray of the
robot. The robot will then deliver it to the specific table and return to the
kitchen and send a feedback signal to the ordering system as a
confirmation of delivery as shown in Figure 3.2.
Fig 3.2 Automated delivery system structure
Besides, every table in the restaurant will be custom made Serving tray.
During the food delivering, the robot will lower the tray into the robot
body to carry the dish with stability and prevent it come into contact with
dust as shown in Figure 3.3. The robot will then travel to the specific
table following the color line on the ground. There are 5 color sensors
placed at the bottom of the robot to detect the line and guide the robot to
the specific table.
Fig 3.3 Inner Part of Robot Design
Once the robot reaches the table, the tray will be lifted up to height of the
table and place the tray on the custom made holder on the table. The
robot will then travel back to the kitchen and be in standby mode. At the
same time, delivery system will also give feedback signal to the ordering
system as a confirmation of delivery.
A. Centre-Wheel Drive Motion System
Once Figure 3.4 shows the overall size of a robot base with 700 mm (W)
* 700 mm (L) * 300 mm (H). The top area which is 700 mm (L) * 500
mm (W) is the area that holds the lifting tray. This holding area giving
the robot better stability is smaller than the bottom area. The inner space
which is 700 mm (L) * 500 mm (W) * 300 mm (H) is a larger empty
space to fix in the electronic control box; this space is surrounded by
strong metal bar that prevents the frail electronic device to be impacted
by any foreign object
to protect the electronic control box.
Fig 3.4 Isotropic View of the Motion System
The robot has to move fast and flexible enough under limited space. The
"walk way" of the robot is usually at the side of the restaurant and the
"walk way" of robot should not have anyone walking on it while robot is
operating so that the delivery system to operate smoothly. It is important
for a restaurant to minimize the space used by the "walk way" of robot in
order to maximize the seating area in a restaurant to serve more
customers at the same time. While a robot is moving forward or
backward, the space needed is exactly the length of the width of the
robot.
When a robot is making a turn, it requires a bigger space to turn
especially for the car-like motion system as shown in Figure 3.5.
Although this type of motion system allows a mobile robot to turn in
relatively faster speed, it required a very large turning radius. Another
common type of motion system is the back-wheel drive motion system
shown in figure 3.6. This type of motion system required less space of
turning, but it still needs a bigger space to make the turn.

3. Fig 3.5 Car like Motion System
Fig 3.6 Back Wheel Drive System
Therefore, the Centre-Wheel Drive Motion System as shown in figure
3.7 is used as the new proposed robot motion system. There are two main
wheels at the centre of the robot. While the robot is moving forward or
backward, the two main wheels will rotate in same direction at the same
speed. For the robot to turn, one wheel will move forward while the other
moves backward simultaneously. This allows the robot to turn with a
zero radius using only the length of the width of the robot.
Fig 3.7 Center Wheel Drive System
B. Lifting System
The robot structure consists of 3 parts; motion system, lifting tray as
shown in Figure 3.8 mounted in the robot body and a serving platform
mounted on the lifting tray.
Fig 3.8 Side View of Lifting System
The Lifting System consists of two main supports to the robot main body
frame; a pulley mounted on the upper part of the body frame, and it is
connected through the steel wire string. One end of the string will be
connected to the serving platform where dish will be placed on it, and
another end is connected to the motor which powers the lifting of the
platform. The motor is mounted at the lower part of the body frame and
powered with lithium battery. There are four limit switches mounted at
the upper and the lower parts of body frame to control the desired height
for lifting. The lifting tray operation is linked with the motion system.
When the motion system halts at the customer dining table, it will send a
signal to activate the motor. The motor retracts the steel wire string and
lift up the platform where the dish is placed. When it
Reaches the desired height and hit the limit switch at the upper part of
main body frame, it will cut off the power supply and the platform will
stop lifting.
Fig 3.9 Lifting Tray Delivers the Dish to the Slot Holder
After the serving platform stops lifting, the motion system will move in
slightly until the serving tray fits into the slot holder to place the food on
the dining table as shown in Figure 3.9. The motor will be powered up
again and retracts the steel wire string in opposite direction, dragging the
serving platform down. The motion system will then move back to the
kitchen.
Power consumption of pulley system is less than other system such as
motor powered lift jack. Furthermore, the pulley system operates and
response promptly once the signal and power is sent. Vice versa, the
hydraulic lift jack requires certain amount of pressure to lift up the piston
which slows down the response time.
The empty space in the robot is used to keep the dish when
The robot is delivering the dish. This will ensure that the dish is being
kept in an enclosed area with minimum contact with surrounding air or
air-condition in the restaurant and keep the food fresh and warm until it
reaches the customer.
Track Guided System plays an important role in this new proposed
automated food delivery system. A track with a contrasting color to
the floor will act as guidance for the robot to maneuver in the room.
A single monolithic CMOS integrated circuit, TCS230 serves as the
color detecting module. TAOS (Texas Advanced Optoelectronic
Solutions) TCS230 is programmable color light-to-frequency
converter which combines configurable silicon photodiodes and a
current-to-frequency converter. This particular surface mounted
device allows direct interface with the
Microcontroller as it functions on TTL (transistor-transistor logic).
The output of the TCS230 is a square wave (50% duty cycle) with
frequency directly proportional to light intensity (irradiance). The
light-to-frequency convertor reads 8 x 8 arrays of photodiodes which
16 of them have a blue filter, 16 photodiodes have green filters, 16
photodiodes have red filters, and 16 photodiodes are clear with no
filters. The photodiodes with the same color filter are connected in
parallel thus which photodiodes to be used is pin-selectable.

4. Fig4.1 TCS 230 Array
The microcontroller will then perform a calculation of the frequency by
detecting the falling edges. With the frequency, the microcontroller will
decide whether the robot is in the line. The TCS230 is able to output
square waves with different frequencies depending on the color of the
reflected line. The output frequency varies accordingly.
Table 4.1 Frequency of Different Color
An apparent difference of frequency can be seen from the output as
shown in Table 4.1 for the microcontroller can digitally recognize the
different color and respond to it. By using this method voltage
comparator is not needed and the response time is faster. Figure 4.2
shows the program that captures the output Frequency of TCS230. In this
case, every input pin can act just like the timer capture peripheral
function.
Fig 4.2 Programming Captured on Output of TCS230
In this segment of programming code, it is the example of how a
particular pin of the microcontroller functions as a frequency capturer. 5
out of 40 pins of the microcontroller which is PICI6F877 can act as the
frequency capturer and thus recognize instantly the color that each color
sensor is detecting.
By recognizing the color, the robot can react according to the logic. By
assuming the line is red (1) and the floor is green, a truth table shown in
table 4.2 can be derived.
Fig 4.2 Truth Table
By programming the robot according to the truth table, the robot is
intelligent enough to get back to the right path even if it is not on the line.
Searching mode refers to the programming loop where the robot will
move accordingly to a sequence and then try to match with one of the
possible states.
IV. DISCUSSIONS AND CONCLUSIONS
The idea of delivering food using a robot is not a new yet there are
several technical difficulties to overcome. First it would be the cost
involved. To convince that this automated food delivery system is
workable, it comes to a point that people will realistically compare the
cost of hiring a worker and buying a robot. Thus it is essential to keep the
cost down.
Speed versus stability is another aspect to be specifically paid attention
to. As the speed increases, the stability of the robot cannot be
compromised. This leads to the determination of the optimum operating
speed. An automated food delivery system using a robot is yet to be
popular in the food and beverage industry. However, once the technical
difficulties can be overcome and improvements are made, the automated
food delivery system using a robot is a possible solution to the issues
faced by thousand of restaurant owners.
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Robots, Science Direct 14 March 2002
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Computer Aided Geometric Design, Elsevier Science B. V.
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Edition 2004, Pearson Education International
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