1. ECE 477 Final Presentation Group 10  Spring 2005 Jer-Wei Lam (Sean) Jacinto Chang Ming Sum Wong Kevin Muthuri Team Lead Web: http://shay.ecn.purdue.edu/~477grp10

2. Outline Project overviewProject overview Block diagramBlock diagram Professional componentsProfessional components Design componentsDesign components Success criteria demonstrationsSuccess criteria demonstrations Individual contributionsIndividual contributions Project summaryProject summary Questions / discussionQuestions / discussion

3. Project Overview Robotic Waitress projectRobotic Waitress project Deliver food to designated table autonomouslyDeliver food to designated table autonomously Comprises of two major components – robot and control centerComprises of two major components – robot and control center Tables’ routes stored in the microcontroller allows control of the robot from control centerTables’ routes stored in the microcontroller allows control of the robot from control center Avoid obstacles using IR sensorsAvoid obstacles using IR sensors

4. Block Diagram

5. Professional Components Constraint analysis and component selection rationaleConstraint analysis and component selection rationale Patent liability analysisPatent liability analysis Reliability and safety analysisReliability and safety analysis Ethical and environmental impact analysisEthical and environmental impact analysis

6. Constraint Analysis Computational RequirementsComputational Requirements –Traveled distance –Sufficient Flash Interface RequirementsInterface Requirements –Servo Motors –IR Sensors –RF communication –LCD Power Supply ConstraintsPower Supply Constraints –5V and 4.8-6V supplies –.5Amps current draw in main board Packaging ConstraintsPackaging Constraints –Limited by chassis of main robot Cost ConstraintsCost Constraints –To be kept to a minimal

7. Component Selection Rationale Robot BaseRobot Base Microcontroller - ATmega32Microcontroller - ATmega32 Digital Sharp GP2D15 IR Distance Measuring SensorsDigital Sharp GP2D15 IR Distance Measuring Sensors 16x2 LCD – Hitachi controller based16x2 LCD – Hitachi controller based LINX 418Mhz 315Mhz RF RXM/TXMLINX 418Mhz 315Mhz RF RXM/TXM Continuous Rotation Ball-Bearing ServosContinuous Rotation Ball-Bearing Servos

8. Patent Liability Analysis Searched on the US Patent and Trademark Office Patent #6,597,143 (2001)Mobile robot system using RF module Patent #6,667,592 (2001)Mapped robot system Patent #6,760,647 (2003)Socially interactive autonomous robot Similar Project “Robotic Waitress” at the University of Rochester No patent is infringed by our project

9. Reliability/Safety Analysis Micro-controller MTTF: 423 yrsMicro-controller MTTF: 423 yrs LM7805 MTTF: 196 yrsLM7805 MTTF: 196 yrs RF Modules MTTF: 13 yrsRF Modules MTTF: 13 yrs Worst case scenario for RF module failure:Worst case scenario for RF module failure: –No communication with control center –Unsatisfied customers

10. Reliability/Safety Analysis Schematic divided into four functional blocksSchematic divided into four functional blocks –Power Circuitry Failure would cause damage to micro & other componentsFailure would cause damage to micro & other components –Micro-controller block Failure would result in random data at output pinsFailure would result in random data at output pins –Sensor block Inability to detect obstacles, food on trayInability to detect obstacles, food on tray –RF Modules Failure causes inability to receive instructions & send alerts to control centerFailure causes inability to receive instructions & send alerts to control center

11. Ethical/Environmental Analysis Potential job loss for human waiters/waitressesPotential job loss for human waiters/waitresses –Higher efficiency and lower operating costs –Leading to increased unemployment. SafetySafety –Currently electronics are not fully protected from outside exposure

12. Lead solder may be health hazardLead solder may be health hazard –During assembly, tray mounting should be done in separate locations. The use of batteries may cause disposal issues.The use of batteries may cause disposal issues. –Potential use of li-po batteries which are environmentally friendly but must be “neutralized” before disposal. Ethical/Environmental Analysis

13. Design Components Packaging design considerationsPackaging design considerations Schematic design considerationsSchematic design considerations PCB layout design considerationsPCB layout design considerations Software design considerationsSoftware design considerations

14. Packaging Design Robot:Robot: Mark III Robot ChassisMark III Robot Chassis 2 Wheels, wedge for support2 Wheels, wedge for support Bright RED wheelsBright RED wheels 8 inch-diameter round tray8 inch-diameter round tray Custom mount for LCD displayCustom mount for LCD display Robot base approx 5” X 4”Robot base approx 5” X 4” Control Center:Control Center: RadioShack Project BoxRadioShack Project Box Size approx 3” X 2” X 1”Size approx 3” X 2” X 1”

15. CAD - Packaging

16. Final packaging

18. Schematic Design Overview of Main Module Schematic

19. Schematic Design Overview of Main Module Schematic Reset Circuitry LM7805 Voltage Regulator

20. Schematic Design Overview of Main Module Schematic

21. Main board size: 4” X 3”Main board size: 4” X 3” Control Center size: 3” X 2.6”Control Center size: 3” X 2.6” Bypass capacitors close to componentsBypass capacitors close to components Ground plane for RF TXM & RXMGround plane for RF TXM & RXM RXM and TXM separatedRXM and TXM separated Short traces to antennaShort traces to antenna Wide traces for ground and powerWide traces for ground and power PCB Layout Design

22. Main Board PCB Layout

23. PCB Layout Design Control Center PCB Layout

24. Software Design – Functionality Control CenterControl Center - Select tables - Display status and alerts MicrocontrollerMicrocontroller - Display status on LCD - Move to the desired table - Detect obstacles and Food - Send alerts back to PC

25. Software Design - FlowChart Main Initialization Self-diagnosis routine Any input data from USART? Decode Instruction Acknowledge/Send Alert to PC Yes No Food Taken? Obstacle Detected? Movement Done? Execute Movement Yes No

26. Software Design – Change of Software Approach Original Approach - PC calculates route and tells robot how to move Current Approach - Routes are stored in robot - PC tells robot which table to go

27. Success Criteria Demonstrations 1.Project-specific success criteria #1 - demo demo 2.Project-specific success criteria #2 - demo demo 3.Project-specific success criteria #3 - demo demo 4.Project-specific success criteria #4 - demo demo 5.Project-specific success criteria #5 - demo demo

28. Individual Contributions Team Leader – Sean Jer-Wei LamTeam Leader – Sean Jer-Wei Lam Team Member 2 – Ming Sum WongTeam Member 2 – Ming Sum Wong Team Member 3 – Kevin MuthuriTeam Member 3 – Kevin Muthuri Team Member 4 – Jacinto ChangTeam Member 4 – Jacinto Chang

29. Team Leader – Sean Jer-Wei Lam Programming RobotProgramming Robot –Motion & Sensor functions –Diagnostics Component ResearchComponent Research Packaging Design & FabricationPackaging Design & Fabrication Board PopulationBoard Population WebmasterWebmaster Testing and DebuggingTesting and Debugging

30. Member 2 – Ming Sum Wong Programming SoftwareProgramming Software –Control Center Application –Synchronization Mechanism –RF & Control Logic Functions Component ResearchComponent Research RF Prototyping and ResearchRF Prototyping and Research RF Communication PrototypingRF Communication Prototyping Testing and DebuggingTesting and Debugging

31. Member 3 – Kevin Muthuri Programming RobotProgramming Robot –Synchronization Mechanism –RF & Control Logic Functions Component ResearchComponent Research RF Communication PrototypingRF Communication Prototyping PCB Layout DesignPCB Layout Design Testing and DebuggingTesting and Debugging

32. Member 4 – Jacinto Chang Implemented Navigation AlgorithmImplemented Navigation Algorithm RF Communication Prototyping and ProtocolRF Communication Prototyping and Protocol Component ResearchComponent Research Board PopulationBoard Population SchematicSchematic Testing and DebuggingTesting and Debugging

33. Project Summary Important lessons learned:Important lessons learned: –Component Selection and Research has to be done early –RF is noisy and unreliable –For PWM to work, an extremely accurate clock is necessary –Total current draw calculations are critical –Must always double check Schematic diagrams and PCB Layouts –Wheel slippage due to insufficient traction –Check for cold solder joints –Prototyping is expensive

34. Project Summary Second iteration enhancements:Second iteration enhancements: –Better positioning system with sensors on the table for location feedback –Use wider wheels for better traction –Provide keypad for food ordering –Voice synthesizer –Human voice recognition

35. Questions / Discussion