ECE 477 Final Presentation ECE 477 Final Presentation Group 10 Group 10 Spring 2005 Spring 2005

Jer-Wei Lam (Sean) Jacinto Chang Ming Sum Wong Kevin Muthuri

Team Lead

Web: http://shay.ecn.purdue.edu/~477grp10

OutlineOutline

• 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

Project OverviewProject Overview

• Robotic Waitress projectRobotic Waitress project• Deliver food to designated table autonomouslyDeliver food to designated table autonomously• Comprises of two major components – robot and Comprises of two major components – robot and

control centercontrol center• Tables’ routes stored in the microcontroller allows Tables’ routes stored in the microcontroller allows

control of the robot from control centercontrol of the robot from control center• Avoid obstacles using IR sensorsAvoid obstacles using IR sensors

Block DiagramBlock Diagram

Professional ComponentsProfessional Components

• Constraint analysis and component selection Constraint analysis and component selection rationalerationale

• Patent liability analysisPatent liability analysis• Reliability and safety analysisReliability and safety analysis• Ethical and environmental impact analysisEthical and environmental impact analysis

Constraint AnalysisConstraint Analysis• Computational RequirementsComputational Requirements

– Traveled distanceTraveled distance– Sufficient FlashSufficient Flash

• Interface RequirementsInterface Requirements– Servo MotorsServo Motors– IR SensorsIR Sensors– RF communicationRF communication– LCDLCD

• Power Supply ConstraintsPower Supply Constraints– 5V and 4.8-6V supplies5V and 4.8-6V supplies– .5Amps current draw in main board.5Amps current draw in main board

• Packaging ConstraintsPackaging Constraints– Limited by chassis of main robotLimited by chassis of main robot

• Cost ConstraintsCost Constraints– To be kept to a minimalTo be kept to a minimal

Component Selection RationaleComponent 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 315MhzLINX 418Mhz 315Mhz RFRF RXM/TXMRXM/TXM

• Continuous Rotation Ball-Bearing ServosContinuous Rotation Ball-Bearing Servos

Patent Liability AnalysisPatent Liability Analysis

Searched on the US Patent and Trademark OfficeSearched on the US Patent and Trademark OfficePatent #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 ProjectSimilar Project

“Robotic Waitress” at the University of Rochester

No patent is infringed by our projectNo patent is infringed by our project

Reliability/Safety AnalysisReliability/Safety Analysis

• Micro-controller MTTF: 423 yrsMicro-controller MTTF: 423 yrs• LM7805 MTTF: 196 yrsLM7805 MTTF: 196 yrs• RF Modules MTTF: 13 yrs RF Modules MTTF: 13 yrs • Worst case scenario for RF module failure:Worst case scenario for RF module failure:

– No communication with control centerNo communication with control center– Unsatisfied customersUnsatisfied customers

Reliability/Safety AnalysisReliability/Safety Analysis

• Schematic divided into four functional blocksSchematic divided into four functional blocks– Power CircuitryPower Circuitry

• Failure would cause damage to micro & other componentsFailure would cause damage to micro & other components

– Micro-controller blockMicro-controller block• Failure would result in random data at output pinsFailure would result in random data at output pins

– Sensor blockSensor block• Inability to detect obstacles, food on trayInability to detect obstacles, food on tray

– RF ModulesRF Modules• Failure causes inability to receive instructions & send alerts to control Failure causes inability to receive instructions & send alerts to control

centercenter

Ethical/Environmental AnalysisEthical/Environmental Analysis• Potential job loss for human Potential job loss for human

waiters/waitresseswaiters/waitresses– Higher efficiency and lower operating Higher efficiency and lower operating

costs costs – Leading to increased unemployment.Leading to increased unemployment.

• SafetySafety– Currently electronics are not fully Currently electronics are not fully

protected from outside exposureprotected from outside exposure

• Lead solder may be health hazardLead solder may be health hazard– During assembly, tray mounting should be During assembly, tray mounting should be

done in separate locations.done in separate locations.• The use of batteries may cause disposal The use of batteries may cause disposal

issues.issues.– Potential use of li-po batteries which are Potential use of li-po batteries which are

environmentally friendly but must be environmentally friendly but must be “neutralized” before disposal.“neutralized” before disposal.

Ethical/Environmental AnalysisEthical/Environmental Analysis

Design ComponentsDesign Components

• Packaging design considerationsPackaging design considerations• Schematic design considerationsSchematic design considerations• PCB layout design considerationsPCB layout design considerations• Software design considerationsSoftware design considerations

Packaging DesignPackaging 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”

CAD - PackagingCAD - Packaging

Final packagingFinal packaging

Final packagingFinal packaging

Schematic DesignSchematic Design

Overview of Main Module Schematic

Schematic DesignSchematic Design

Overview of Main Module Schematic

Reset Circuitry

LM7805 Voltage Regulator

Schematic DesignSchematic Design

Overview of Main Module Schematic

• 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 & RXM Ground plane for RF TXM & RXM • RXM and TXM separated RXM and TXM separated • Short traces to antennaShort traces to antenna• Wide traces for ground and powerWide traces for ground and power

PCB Layout DesignPCB Layout Design

PCB Layout DesignPCB Layout Design

Main Board PCB Layout

PCB Layout DesignPCB Layout Design

Control Center PCB Layout

Software Design – FunctionalitySoftware Design – Functionality

• Control CenterControl Center

- Select tables- Select tables

- Display status and alerts- Display status and alerts

• MicrocontrollerMicrocontroller

- Display status on LCD- Display status on LCD

- Move to the desired table- Move to the desired table

- Detect obstacles and Food- Detect obstacles and Food

- Send alerts back to PC- Send alerts back to PC

Software Design - FlowChartSoftware Design - FlowChartMain 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

Software Design – Change of Software ApproachSoftware Design – Change of Software Approach

Original ApproachOriginal Approach

- PC calculates route and tells robot how to - PC calculates route and tells robot how to movemove

Current ApproachCurrent Approach

- Routes are stored in robot- Routes are stored in robot

- PC tells robot which table to go- PC tells robot which table to go

Success Criteria DemonstrationsSuccess Criteria Demonstrations

1.1. Project-specific success criteria #1 - Project-specific success criteria #1 - demodemo

2.2. Project-specific success criteria #2 - Project-specific success criteria #2 - demodemo

3.3. Project-specific success criteria #3 - Project-specific success criteria #3 - demodemo

4.4. Project-specific success criteria #4 - Project-specific success criteria #4 - demodemo

5.5. Project-specific success criteria #5 - Project-specific success criteria #5 - demodemo

Individual ContributionsIndividual 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

Team Leader – Sean Jer-Wei LamTeam Leader – Sean Jer-Wei Lam

• Programming RobotProgramming Robot– Motion & Sensor functionsMotion & Sensor functions– DiagnosticsDiagnostics

• Component ResearchComponent Research• Packaging Design & FabricationPackaging Design & Fabrication• Board PopulationBoard Population• WebmasterWebmaster• Testing and DebuggingTesting and Debugging

Member 2 – Ming Sum WongMember 2 – Ming Sum Wong

• Programming SoftwareProgramming Software– Control Center ApplicationControl Center Application– Synchronization MechanismSynchronization Mechanism– RF & Control Logic FunctionsRF & Control Logic Functions

• Component ResearchComponent Research• RF Prototyping and ResearchRF Prototyping and Research• RF Communication PrototypingRF Communication Prototyping• Testing and DebuggingTesting and Debugging

Member 3 – Kevin MuthuriMember 3 – Kevin Muthuri

• Programming RobotProgramming Robot– Synchronization MechanismSynchronization Mechanism– RF & Control Logic FunctionsRF & Control Logic Functions

• Component ResearchComponent Research• RF Communication PrototypingRF Communication Prototyping• PCB Layout DesignPCB Layout Design• Testing and DebuggingTesting and Debugging

Member 4 – Jacinto ChangMember 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

Project SummaryProject Summary

• Important lessons learned:Important lessons learned:– Component Selection and Research has to be Component Selection and Research has to be

done earlydone early– RF is noisy and unreliableRF is noisy and unreliable– For PWM to work, an extremely accurate clock is For PWM to work, an extremely accurate clock is

necessarynecessary– Total current draw calculations are criticalTotal current draw calculations are critical– Must always double check Schematic diagrams Must always double check Schematic diagrams

and PCB Layoutsand PCB Layouts– Wheel slippage due to insufficient tractionWheel slippage due to insufficient traction– Check for cold solder jointsCheck for cold solder joints– Prototyping is expensivePrototyping is expensive

Project SummaryProject Summary

• Second iteration enhancements:Second iteration enhancements:– Better positioning system with sensors on Better positioning system with sensors on

the table for location feedbackthe table for location feedback– Use wider wheels for better tractionUse wider wheels for better traction– Provide keypad for food orderingProvide keypad for food ordering– Voice synthesizerVoice synthesizer– Human voice recognitionHuman voice recognition

Questions / DiscussionQuestions / Discussion