RFID Based Line Follower Robot Used as a Service Provider in AutomatedRestaurant SystemArpit Gupte, Kartik Makadia, Debostuti Das, Deepesh Kumar AgarwalStudent, 4THYear, Department of Computer Science and EngineeringEast West Institute of Technology (VTU)Bangalore, Karnataka.India1arpitgupte@email@example.com@firstname.lastname@example.orgAbstract-More people prefer to dine out nowadays and the foodand beverage industry has to revolutionize its way of servingcustomers in order to remain sustainable to the growingpopulation. This research aims at designing an Automated FoodDelivery System to overcome this problem. The new proposedsystem structure consists of color lines that are drawn on therestaurant ground and they link all tables to the kitchen servingas a guiding track; a robot that is in sync with the orderingsystem will serve. When customers place their order through theordering system, the system will send the order to the kitchen.Once the dish is prepared, a signal will be sent to the robot thenrobot will then deliver it to the specific table and return to thekitchen and send a feedback signal to the ordering system as aconfirmation of delivery. This system is yet to be popular in thefood and beverage industry and there are several technicaldifficulties to be overcome. However, once the technicaldifficulties can be overcome and improvements are made, theautomated food delivery system using a robot is a possiblesolution to the issues faced by thousand of restaurant owners.I. INTRODUCTIONMORE and more people prefer to dine out nowadays. This is trueespecially for the working population. Take Mumbai, India as anexample, the number of working population as shown in Figure 1.1 mayreflect the number of people dining out during lunch hour daily.Fig 1.1 Principal Statistics of Labor Force, IndiaThe number is telling a fact that the food and beverage industry has torevolutionize its way of serving customers in order to remain sustainableto the growing population. Thus, restaurants have come out with manycreative, effective and user-friendly ways to serve and deliver food.Currently, Food Ordering and Delivering Systems can be generallyclassified as Conventional Waiter-Serving System, Self-Service BuffetSystem, Pen-and-Paper Self-Ordering System, Kaiten Conveyor BeltSystem (US Patent 5419410-Delivery system) and Fast-Food Self-Carrying System (US Patent 4245720 - Fast food restaurant). Bottleneckwas found in each of these systems as the number of customers increasessignificantly. The Conventional Waiter-Serving System has a drawbackin hiring of good employees. As for the Conveyor Belt Systemrestaurants, a large and fixed area is needed whichGreatly reduces the seating area available in the restaurant. Thus, thisresearch aims at designing an Automated Food Delivery System toovercome the above mentioned issues with the current systems.II. BACKGROUND REVIEWA. Hydraulic System for Serving FoodWith the introduction of automatic food display and service systems asushi chef can serve a greater number of customers while providing freshsushi to customers as soon as the customers are seated. One such fooddisplay discloses a continuous chain of small food carriages having theshape of boats arranged in a watercourse. The bow of each boat isphysically attached to the stem of an adjacent boat via a chain or otherinterconnecting member. Customers seated around the watercourse willremove their food order from the boats as they pass by. The chefmonitors and replenishes empty boats with the appropriate variety ofsushi.[IS]B. Conveyor System for Drive-In RestaurantA conveyor system for drive-in restaurants consists of a plurality of tray-supporting carriages which are electrically driven to move along a tracksystem including rails from which they derive their power. This inventionrelates to new and useful improvement in conveyor systems, especiallyadapted for use in drive-in restaurants. The food ordered by passengers inautomobiles parked at designated stations is delivered automatically toproper stations from the restaurant building on trays moved by theconveyor. The trays are returned by the conveyor to the restaurantbuilding when the food has been consumed, and the trays may also be
used collecting the money in payment for the food. The requirement forlive waitresses or waiters, commonly known as "carhops, is virtuallyeliminated, permitting a great saving in salaries.C. Automatic Dish Serving SystemThis invention relates to an automatic dish serving systemCapable of effectively serving dishes including food and drink tocustomers at restaurant. This system provides an automatic dish servingsystem comprising a supply centre for supplying dish such as food anddrink to a customers seat to which the food and drink are served; acarrier wagon travelling along a route between the supply centre and thecustomers seat; and a route guiding means for guiding the carrier wagonas to take an appropriate route, wherein the customers seat is providedwith a turntable for retaining the served dishes of food and drink, andprovided with an arrival portion to which the carrier wagon arrives; andwherein theCarrier wagon is provided with a transfer means for transferring the disharticles between the turntable and the carrier wagon.III. NEW PROPOSED SYSTEM STRUCTUREThe new proposed system structure as shown in Figure 3.1 consists ofcolor lines that are drawn on the restaurant ground and they link all tablesto the kitchen as guiding track; a robot that synchronized with theordering system to know which table to serve and which track to follow.Fig 3.1 New Proposed System StructureWhen customers place their order though the ordering system; the systemwill send the order to the kitchen. Once the dish is prepared, a signal willbe sent to the robot while the chef places those dish on the tray of therobot. The robot will then deliver it to the specific table and return to thekitchen and send a feedback signal to the ordering system as aconfirmation of delivery as shown in Figure 3.2.Fig 3.2 Automated delivery system structureBesides, every table in the restaurant will be custom made Serving tray.During the food delivering, the robot will lower the tray into the robotbody to carry the dish with stability and prevent it come into contact withdust as shown in Figure 3.3. The robot will then travel to the specifictable following the color line on the ground. There are 5 color sensorsplaced at the bottom of the robot to detect the line and guide the robot tothe specific table.Fig 3.3 Inner Part of Robot DesignOnce the robot reaches the table, the tray will be lifted up to height of thetable and place the tray on the custom made holder on the table. Therobot will then travel back to the kitchen and be in standby mode. At thesame time, delivery system will also give feedback signal to the orderingsystem as a confirmation of delivery.A. Centre-Wheel Drive Motion SystemOnce 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) * 500mm (W) is the area that holds the lifting tray. This holding area givingthe robot better stability is smaller than the bottom area. The inner spacewhich is 700 mm (L) * 500 mm (W) * 300 mm (H) is a larger emptyspace to fix in the electronic control box; this space is surrounded bystrong metal bar that prevents the frail electronic device to be impactedby any foreign objectto protect the electronic control box.Fig 3.4 Isotropic View of the Motion SystemThe 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 isoperating so that the delivery system to operate smoothly. It is importantfor a restaurant to minimize the space used by the "walk way" of robot inorder to maximize the seating area in a restaurant to serve morecustomers at the same time. While a robot is moving forward orbackward, the space needed is exactly the length of the width of therobot.When a robot is making a turn, it requires a bigger space to turnespecially for the car-like motion system as shown in Figure 3.5.Although this type of motion system allows a mobile robot to turn inrelatively faster speed, it required a very large turning radius. Anothercommon type of motion system is the back-wheel drive motion systemshown in figure 3.6. This type of motion system required less space ofturning, but it still needs a bigger space to make the turn.
Fig 3.5 Car like Motion SystemFig 3.6 Back Wheel Drive SystemTherefore, the Centre-Wheel Drive Motion System as shown in figure3.7 is used as the new proposed robot motion system. There are two mainwheels at the centre of the robot. While the robot is moving forward orbackward, the two main wheels will rotate in same direction at the samespeed. For the robot to turn, one wheel will move forward while the othermoves backward simultaneously. This allows the robot to turn with azero radius using only the length of the width of the robot.Fig 3.7 Center Wheel Drive SystemB. Lifting SystemThe robot structure consists of 3 parts; motion system, lifting tray asshown in Figure 3.8 mounted in the robot body and a serving platformmounted on the lifting tray.Fig 3.8 Side View of Lifting SystemThe Lifting System consists of two main supports to the robot main bodyframe; a pulley mounted on the upper part of the body frame, and it isconnected through the steel wire string. One end of the string will beconnected to the serving platform where dish will be placed on it, andanother end is connected to the motor which powers the lifting of theplatform. The motor is mounted at the lower part of the body frame andpowered with lithium battery. There are four limit switches mounted atthe upper and the lower parts of body frame to control the desired heightfor lifting. The lifting tray operation is linked with the motion system.When the motion system halts at the customer dining table, it will send asignal to activate the motor. The motor retracts the steel wire string andlift up the platform where the dish is placed. When itReaches the desired height and hit the limit switch at the upper part ofmain body frame, it will cut off the power supply and the platform willstop lifting.Fig 3.9 Lifting Tray Delivers the Dish to the Slot HolderAfter the serving platform stops lifting, the motion system will move inslightly until the serving tray fits into the slot holder to place the food onthe dining table as shown in Figure 3.9. The motor will be powered upagain and retracts the steel wire string in opposite direction, dragging theserving platform down. The motion system will then move back to thekitchen.Power consumption of pulley system is less than other system such asmotor powered lift jack. Furthermore, the pulley system operates andresponse promptly once the signal and power is sent. Vice versa, thehydraulic lift jack requires certain amount of pressure to lift up the pistonwhich 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 beingkept in an enclosed area with minimum contact with surrounding air orair-condition in the restaurant and keep the food fresh and warm until itreaches the customer.Track Guided System plays an important role in this new proposedautomated food delivery system. A track with a contrasting color tothe floor will act as guidance for the robot to maneuver in the room.A single monolithic CMOS integrated circuit, TCS230 serves as thecolor detecting module. TAOS (Texas Advanced OptoelectronicSolutions) TCS230 is programmable color light-to-frequencyconverter which combines configurable silicon photodiodes and acurrent-to-frequency converter. This particular surface mounteddevice 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) withfrequency directly proportional to light intensity (irradiance). Thelight-to-frequency convertor reads 8 x 8 arrays of photodiodes which16 of them have a blue filter, 16 photodiodes have green filters, 16photodiodes have red filters, and 16 photodiodes are clear with nofilters. The photodiodes with the same color filter are connected inparallel thus which photodiodes to be used is pin-selectable.
Fig4.1 TCS 230 ArrayThe microcontroller will then perform a calculation of the frequency bydetecting the falling edges. With the frequency, the microcontroller willdecide whether the robot is in the line. The TCS230 is able to outputsquare waves with different frequencies depending on the color of thereflected line. The output frequency varies accordingly.Table 4.1 Frequency of Different ColorAn apparent difference of frequency can be seen from the output asshown in Table 4.1 for the microcontroller can digitally recognize thedifferent color and respond to it. By using this method voltagecomparator is not needed and the response time is faster. Figure 4.2shows the program that captures the output Frequency of TCS230. In thiscase, every input pin can act just like the timer capture peripheralfunction.Fig 4.2 Programming Captured on Output of TCS230In this segment of programming code, it is the example of how aparticular pin of the microcontroller functions as a frequency capturer. 5out of 40 pins of the microcontroller which is PICI6F877 can act as thefrequency capturer and thus recognize instantly the color that each colorsensor is detecting.By recognizing the color, the robot can react according to the logic. Byassuming the line is red (1) and the floor is green, a truth table shown intable 4.2 can be derived.Fig 4.2 Truth TableBy programming the robot according to the truth table, the robot isintelligent 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 willmove accordingly to a sequence and then try to match with one of thepossible states.IV. DISCUSSIONS AND CONCLUSIONSThe idea of delivering food using a robot is not a new yet there areseveral technical difficulties to overcome. First it would be the costinvolved. To convince that this automated food delivery system isworkable, it comes to a point that people will realistically compare thecost of hiring a worker and buying a robot. Thus it is essential to keep thecost down.Speed versus stability is another aspect to be specifically paid attentionto. As the speed increases, the stability of the robot cannot becompromised. This leads to the determination of the optimum operatingspeed. An automated food delivery system using a robot is yet to bepopular in the food and beverage industry. However, once the technicaldifficulties can be overcome and improvements are made, the automatedfood delivery system using a robot is a possible solution to the issuesfaced by thousand of restaurant owners.REFERENCES[I) K. Demirli., M.Khoshnejad, Autonomous parallel parking of a carlikemobile robot by a neuro-Juzzy sensor-based controller, ScienceDirect 27 January 2009(2) V.M. BUDANOV and Yeo A. DEVYANIN, The Motions of WheeledRobots, Science Direct 14 March 2002(3) Labour Force Survey Report of MalaySia, First Quarter 2009(4) Gerald E. Farin, Josef Hoschek, Myung-Soo Kim, Handbook ofComputer Aided Geometric Design, Elsevier Science B. V.(5) Robert L. Mott, Machine Elements In Mechanical Design, FourthEdition 2004, Pearson Education International(6) John J.Craig, Introduction To Robotic And Control, Third Edition2005, Pearson Education International(7) Karl Lunt, Build Your Own Robot, 2000, A K Peters.