RFID Based Line Follower Robot Used as a Service Provider in Automated Restaurant System

Arpit Gupte, Kartik Makadia, Debostuti Das, Deepesh Kumar AgarwalStudent, 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

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 systemCapable 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 theCarrier 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 objectto 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.

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 itReaches 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 whenThe 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 theMicrocontroller 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.

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.

REFERENCES

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