IMDL Summer IMDL Summer 2007: RoBeDeS2007: RoBeDeS

by David Ladolcettaby David Ladolcetta

SummarySummary

PlatformPlatform SensorsSensors BehaviorsBehaviors

Platform DesignPlatform Design

3 layers3 layers

Bottom LayerBottom Layer

Motors and wheels mounted belowMotors and wheels mounted below Bumper attached to frontBumper attached to front Servo add-on BoardServo add-on Board MAVRIC boardMAVRIC board 3 Battery Packs3 Battery Packs SONARSONAR JTAGJTAG

Middle LayerMiddle Layer

Drink platformDrink platform CdS Cells under drinkCdS Cells under drink Status LED arrayStatus LED array

Top LayerTop Layer

Drink stabilizerDrink stabilizer Pyro SensorPyro Sensor LCD screenLCD screen

SensorsSensors

BumpBump SonarSonar CdSCdS PIRPIR

BumpBump Backup Obstacle AvoidanceBackup Obstacle Avoidance 3 on front3 on front

Bumper connecting all threeBumper connecting all three Coat hanger inside Rubber weather Coat hanger inside Rubber weather

strippingstripping

1 on back for reverse Obstacle 1 on back for reverse Obstacle avoidanceavoidance

SonarSonar

Main Obstacle avoidanceMain Obstacle avoidance Mounted to minimize middle blind Mounted to minimize middle blind

spot and maximize angle of viewingspot and maximize angle of viewing

CdS Drink detectorCdS Drink detector

Senses amount of lightSenses amount of light 3 mounted under middle layer under 3 mounted under middle layer under

drinksdrinks AD reads ~250 when covered, <100 AD reads ~250 when covered, <100

when uncoveredwhen uncovered

Pyro Infra Red (PIR)Pyro Infra Red (PIR)

Hacked Wal-Mart Motion detecting Hacked Wal-Mart Motion detecting night lightnight light

Senses moving heatSenses moving heat Mounted on a sweeping servo to get Mounted on a sweeping servo to get

relative motion from static relative motion from static

peoplepeople Cardboard “Cone” to Cardboard “Cone” to

narrow field of visionnarrow field of vision

BehaviorsBehaviors

Person seekingPerson seeking Obstacle avoidanceObstacle avoidance Person TrackingPerson Tracking Drink removal waitingDrink removal waiting Tray emptyTray empty

Person seeking behaviorPerson seeking behavior The robot moves forward while panning The robot moves forward while panning

the servo back and forth 120 degreesthe servo back and forth 120 degrees Continuously checks PIR on AD port 0 Continuously checks PIR on AD port 0

for any value above 170 and below 100 for any value above 170 and below 100 on a 0-255 scale. If triggered, enters on a 0-255 scale. If triggered, enters person tracking mode.person tracking mode.

Simultaneously checks for Sonar or Simultaneously checks for Sonar or bump sensors – if triggered, enters bump sensors – if triggered, enters obstacle avoidance modeobstacle avoidance mode

Obstacle Avoidance Obstacle Avoidance BehaviorBehavior

When sonar or bump sensors triggerWhen sonar or bump sensors trigger Stops motorsStops motors Moves backward for 1 secondMoves backward for 1 second Turns randomly left or right 90 Turns randomly left or right 90

degreesdegrees Moves forward and returns to Moves forward and returns to

Person seeking modePerson seeking mode

Person Tracking Person Tracking BehaviorBehavior

When pyro triggers meaning a person (or When pyro triggers meaning a person (or other heat source) is foundother heat source) is found

Reads direction servo is facing and turns Reads direction servo is facing and turns platform toward that directionplatform toward that direction

Moves forward and continues sweeping servoMoves forward and continues sweeping servo If person is within +/- 15 degrees of center If person is within +/- 15 degrees of center

keep moving until sonar detects something keep moving until sonar detects something within 3 in.within 3 in.

If person is outside of threshold, robot will If person is outside of threshold, robot will adjust platform direction accordinglyadjust platform direction accordingly

Person Tracking (cont’d)Person Tracking (cont’d)

If person is not found after 3 full If person is not found after 3 full sweeps then robot spins ~400 sweeps then robot spins ~400 degrees to re-find person, then degrees to re-find person, then adjusts accordingly when foundadjusts accordingly when found

If person is fully lost, returns to If person is fully lost, returns to Person seekingPerson seeking

Once sonar detects person within Once sonar detects person within 3in, stops movement and enters 3in, stops movement and enters waiting modewaiting mode

Waiting BehaviorWaiting Behavior

Continuously checks CdS cells on AD Continuously checks CdS cells on AD port 1-3 to detect any removal of a port 1-3 to detect any removal of a drinkdrink

Once drink is removed or if no drink is Once drink is removed or if no drink is removed after 8 seconds, RoBeDeS removed after 8 seconds, RoBeDeS turns 180 degrees and returns to turns 180 degrees and returns to person seeking modeperson seeking mode

If drink is removed and no more drinks If drink is removed and no more drinks remain, enters tray empty moderemain, enters tray empty mode

Tray Empty BehaviorTray Empty Behavior

Turns 180 degreesTurns 180 degrees Finds nearest wallFinds nearest wall Shuts AD off and blinks signifying it Shuts AD off and blinks signifying it

needs to be refilled and resetneeds to be refilled and reset