1. IMDL Summer 2007: RoBeDeS
by David Ladolcetta

2. Summary
Platform
Sensors
Behaviors

3. Platform Design
3 layers

4. Bottom Layer Motors and wheels mounted below Bumper attached to front
Servo add-on Board
MAVRIC board
3 Battery Packs
SONAR
JTAG

5. Middle Layer
Drink platform
CdS Cells under drink
Status LED array

6. Top Layer
Drink stabilizer
Pyro Sensor
LCD screen

7. Sensors
Bump
Sonar
CdS
PIR

8. Bump Backup Obstacle Avoidance 3 on front
Bumper connecting all three
Coat hanger inside Rubber weather stripping
1 on back for reverse Obstacle avoidance

9. Sonar Main Obstacle avoidance
Mounted to minimize middle blind spot and maximize angle of viewing

10. CdS Drink detector Senses amount of light
3 mounted under middle layer under drinks
AD reads ~250 when covered, <100 when uncovered

11. Pyro Infra Red (PIR) Hacked Wal-Mart Motion detecting night light
Senses moving heat
Mounted on a sweeping servo to get relative motion from static
people
Cardboard “Cone” to
narrow field of vision

12. Behaviors Person seeking Obstacle avoidance Person Tracking
Drink removal waiting
Tray empty

13. Person seeking behavior
The robot moves forward while panning the servo back and forth 120 degrees
Continuously checks PIR on AD port 0 for any value above 170 and below 100 on a scale. If triggered, enters person tracking mode.
Simultaneously checks for Sonar or bump sensors – if triggered, enters obstacle avoidance mode

14. Obstacle Avoidance Behavior
When sonar or bump sensors trigger
Stops motors
Moves backward for 1 second
Turns randomly left or right 90 degrees
Moves forward and returns to Person seeking mode

15. Person Tracking Behavior
When pyro triggers meaning a person (or other heat source) is found
Reads direction servo is facing and turns platform toward that direction
Moves forward and continues sweeping servo
If person is within +/- 15 degrees of center keep moving until sonar detects something within 3 in.
If person is outside of threshold, robot will adjust platform direction accordingly

16. Person Tracking (cont’d)
If person is not found after 3 full sweeps then robot spins ~400 degrees to re-find person, then adjusts accordingly when found
If person is fully lost, returns to Person seeking
Once sonar detects person within 3in, stops movement and enters waiting mode

17. Waiting Behavior
Continuously checks CdS cells on AD port 1-3 to detect any removal of a drink
Once drink is removed or if no drink is removed after 8 seconds, RoBeDeS turns 180 degrees and returns to person seeking mode
If drink is removed and no more drinks remain, enters tray empty mode

18. Tray Empty Behavior Turns 180 degrees Finds nearest wall
Shuts AD off and blinks signifying it needs to be refilled and reset