Exploring withExploring withLego RobotsLego Robots

Daniel LimbrickDaniel Limbrick (Texas A&M University)(Texas A&M University)

Emily SherrillEmily Sherrill (Tennessee Tech University)(Tennessee Tech University)

Final Report Final Report Overview:Overview:

ChallengeChallenge Final Robot DesignFinal Robot Design Mid-Summer Mid-Summer

SummarySummary Progress of Second Progress of Second

TermTerm PC/Robot SimulationPC/Robot Simulation

Maze FrameMaze Frame ControllerController Robot MovementRobot Movement CircuitCircuit ProblemsProblems ConclusionConclusion

The Challenge:The Challenge:

Use a Bluetooth device to adapt a Lego Use a Bluetooth device to adapt a Lego Mindstorms robot for wireless communicationMindstorms robot for wireless communication

Using the Java programming language, make Using the Java programming language, make the robot explore a maze and communicate the the robot explore a maze and communicate the layout of the maze back to a computerlayout of the maze back to a computer

Create a controller to allow the robot to be Create a controller to allow the robot to be driven from the computer screendriven from the computer screen

Final Design Final Design of of Our Lego RobotOur Lego Robot

Two MotorsTwo Motors Two Rotation Two Rotation

SensorsSensors One Touch SensorOne Touch Sensor RCX Lego BrickRCX Lego Brick

Mid-Summer SummaryMid-Summer Summary AccomplishmentsAccomplishments

Straight line travelStraight line travel Maze Mapping Maze Mapping

AlgorithmAlgorithm Go-to-Point AlgorithmGo-to-Point Algorithm DLL ProtocolDLL Protocol Untested SimulatorUntested Simulator

Mid-Summer SummaryMid-Summer Summary ProblemsProblems

Wheels stick, slip, or slide depending on Wheels stick, slip, or slide depending on surfacesurface

Rotations are not always accurate or Rotations are not always accurate or consistentconsistent

Different motor strengthsDifferent motor strengths Touch sensor activationTouch sensor activation

Progress of Second Progress of Second TermTerm

Tasks Remaining at Mid-Summer ReportTasks Remaining at Mid-Summer Report Making robot movement more accurateMaking robot movement more accurate Sending/receiving information from actual robotSending/receiving information from actual robot Completing user-click point travelCompleting user-click point travel Expanding the ControllerExpanding the Controller

Accomplishments during Second TermAccomplishments during Second Term Simulation of PC/Robot CommunicationSimulation of PC/Robot Communication User-Click Point Travel/ControllerUser-Click Point Travel/Controller Robot MovementRobot Movement Sending/Receiving from actual robotSending/Receiving from actual robot

Simulation of PC/Robot Simulation of PC/Robot CommunicationCommunication

Designed to locate flaws in the algorithm logic Designed to locate flaws in the algorithm logic and in the program codingand in the program coding

After correcting initial errors, the simulation After correcting initial errors, the simulation works successfully for both the maze mapping works successfully for both the maze mapping algorithm and the go-to-point algorithmalgorithm and the go-to-point algorithm

Converted string movement commands to byte Converted string movement commands to byte movement commands, so that the command movement commands, so that the command transfers from robot to PC are completed with transfers from robot to PC are completed with minimal chance of data alteration or lose.minimal chance of data alteration or lose.

Maze FrameMaze Frame Creates a visual Creates a visual

representation of the representation of the mazemaze

Maze Mapping DisplayMaze Mapping Display Updates the display of Updates the display of

the maze as the robot the maze as the robot discovers the layout discovers the layout during the Maze during the Maze Mapping AlgorithmMapping Algorithm Depicts the robot view Depicts the robot view

of the mazeof the maze

MazeMaze FrameFrame Go-to-Point DisplayGo-to-Point Display

Displays the moves Displays the moves that the robot will that the robot will perform before it perform before it actually starts the actually starts the processing of the Go-processing of the Go-to-Point algorithm to-Point algorithm commandscommands

ControllerController User-Point Click TravelUser-Point Click Travel

Uses the MazeFrame class Uses the MazeFrame class with a MouseListenerwith a MouseListener

When the user clicks on a When the user clicks on a point in the graphical point in the graphical representation of the maze, representation of the maze, the MouseListener the MouseListener determines where the click determines where the click occurred, translates that occurred, translates that point into the equivalent point into the equivalent maze dimension point, and maze dimension point, and then send the point to the go-then send the point to the go-to-point algorithmto-point algorithm

Controller ExpansionController Expansion Allows the user to move the Allows the user to move the

robot using the arrow keysrobot using the arrow keys Cancelled due to timeCancelled due to time

Examples of Test MazesExamples of Test Mazes

Starting at any PointStarting at any Point

Robot MovementRobot Movement Improved accuracy of the rotations Improved accuracy of the rotations

(still not 100%)(still not 100%) RobotLejos classRobotLejos class

Download onto robotDownload onto robot Contains all robot movement methodsContains all robot movement methods Methods in class can be called by PCMethods in class can be called by PC

CircuitCircuit Tested the Bluetooth circuit that will be used on Tested the Bluetooth circuit that will be used on

the robot by linking it to the computer. The the robot by linking it to the computer. The circuit generated values and transmitted it to circuit generated values and transmitted it to the computer's serial port. The output was the computer's serial port. The output was displayed on the HyperTerminal. displayed on the HyperTerminal.

Accuracy of the output was dependant upon Accuracy of the output was dependant upon the voltage from the battery and the resistance the voltage from the battery and the resistance of the potentiometer. of the potentiometer.

Must be properly calibrated before useMust be properly calibrated before use

ProblemsProblems Discovered that scrolling up in Discovered that scrolling up in

the command line window the command line window while the program is running while the program is running causes a back up in the causes a back up in the communication portcommunication port With strings: becomes one With strings: becomes one

long continuous stringlong continuous string With bytes: causes the With bytes: causes the

program to miss bytes program to miss bytes Previous robot movement Previous robot movement

issue still existissue still exist The first DLL would not The first DLL would not

release control over the release control over the communication serial port for communication serial port for the following DLL to have the following DLL to have access to itaccess to it

ProblemsProblems Problems with the circuitProblems with the circuit

Overloads LEDs located Overloads LEDs located at the front of the RCX at the front of the RCX bricks.bricks.

Originally used wrong Originally used wrong capacitorcapacitor

Excess noise sent through Excess noise sent through the serial port causes the serial port causes errors in the DLL’s ability errors in the DLL’s ability to receive information to receive information accurately.accurately.

As battery power As battery power fluctuates, the fluctuates, the potentiometer has to be potentiometer has to be recalibrated.recalibrated.

Conclusion and Conclusion and ImprovementsImprovements

Successfully simulated entire project Partially demonstrated project with robot Future considerations

Using wheels with less friction (robot movement accuracy)

Using the new RCX brick with built-in Bluetooth capability (reliable communication)

Our PosterOur Poster

Exploring withExploring withLego RobotsLego Robots

Daniel LimbrickDaniel Limbrick (Texas A&M University)(Texas A&M University)

Emily SherrillEmily Sherrill (Tennessee Tech University)(Tennessee Tech University)

Thanks:Thanks: Grad Student Advisor: Daniel B.Grad Student Advisor: Daniel B. Dr. KarsaiDr. Karsai Ryan ThibodeauxRyan Thibodeaux ALL OF ISIS!ALL OF ISIS!