Post on 23-Feb-2016
description
ECE/ME 491/2 Group 4Winter 2009
Benjamin ChenSuhail Gul
Wai-Sze LokRob MerkleBrian Shaw
Renee Soenen
Objective: To build an autonomous firefighting robot
Structural Design Considerations Small or 0° turn radiusGiven size restriction and ground
clearanceFrictionType of drive-trainWeight and center of gravity location
Wheels First considered to determine range of
chassis size to work withQuantity and type which help with finalizing
drive-trainExplored track style, multi-directional and
standard hobbyist rubber wheelsSize to provide enough ground clearance
Chassis and Drive-trainShapes and sizes
Square, triangular and rectangularMaterial
Lightweight and easy to machineDeck quantityQuantity, speed and torque of motorsSteering mechanism
Chassis and Drive-trainCurrent DesignChose optimal shape for best wheel
configuration for designAluminum chassisTwo decks Four modified servos to drive
Possible Structural IssuesAmount of stress on shaft of servos
Possibly perform FEA to determine max stressClearance with face of wheels
Change wheels (last resort)Vibration
Change thickness or material of chassis for more flexibility
Shock absorption on wheel (last resort)
Rendered output of robot
DC Motor vs Modified ServoDC Motor: Energy efficient Powerful
Modified Servo: Excellent control of speed Sufficient torque and speed in a compact
unit Internally geared
Parameter on picking servoWeight of the robotDesired terrainDesired velocity and accelerationVoltagePower consumptioncontrollability
Robot Motor Factor (RMF)rpstorqueRMF
2velocityonacceleratiweightRMF
Fire Extinguishing MechanismDidn’t want to use airSeveral different ideasCO2
System similar to a paintball gunPaintball gun worked, but not feasible
Foam SpraySmall travel shaving cream canOnly shot a stream about 3 in.
Fire Extinguishing MechanismSpray Bottle
Febreeze bottle, other press down bottlePump-spray system (current)
Windshield washer nozzles
Fire Extinguishing MechanismFuture work
Testing for volumetric flow rate and operating pressure
Buying misting nozzlesTesting
Range, operation time, etc.
Constraints for electronic platformSizePower requirementProcessing abilityI/O optionsProgrammability
Possible platform optionsMotorola HCS12 based EVBplus
MiniDragon+ or MiniDragon-Plus2 microcontroller
Xilinx Spartan3 based development boardTexas Instruments OMAP based Gumstix
Overo or Marvell PXA270 based Gumstix Verdex Pro
ADI Blackfin based microcontrollerIntel Atom based D945GCLF development
board
Remaining Work• Working on basic design requirements.
• Custom building parts required for the base.
• Working on basic design.
• Connecting the sensors and servos.
• Working on circuits and power requirement.
PROGRAMMINGWorking on programming servos
Working on programming microcontroller for connecting sensors.
Working on pathfinding algorithms
NavigationFirst ideas for navigation:• Strictly sensor-based travel.
• Specific behavior algorithms, such as straight-line and always-left-turn kind of algorithms.
• Knowledge of the house layout via a stored map.
NavigationThe robots primary method of understanding the
environment will be vision via a camera.
The camera-based vision system is complemented by an array of sensors for redundancy and verification purposes.
Implementing a vision-based system is more technically challenging than the previous ideas, but the benefits of vision are many.
Original project timelineA tad too optimistic…
Any Questions?We won’t tell you too many details of our
proprietary implementation…