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|Target Environment||Locomotion Method|
|Sensors / Input Devices||Actuators / Output Devices|
|2 EG&G Thermopiles
3 Omron optical sensors
|Two unipolar stepper motors
|Control Method||Power Source|
|CPU Type||Operating System|
|2 Phillips 87C752, 1 Motorola 68HC11F1||N/A|
|Time to build||Cost to build|
|URL for more information|
|Rosie was built in three stages and designed to compete in the fire fighting robot contest. The first stage was a rolling base, then a navigation section, the third was the fire detection and extinguishing section. By building each as an individually functioning unit I was able to cut down my development time.
The first stage consisted of two drive wheels mounted in a 8 inch diameter Plexiglas disk on the center axis. On a perpendicular axis were two casters. The stepper motors drove the drive wheels via a gear mounted to each. The steppers were "stepped" using a darlington transistor array with the stepper pattern counted off using a 87C752 microcontroller.
The navigation unit was built with a 68HC11F1 controller wirewrap board mounted on a 8 inch diameter Plexiglas disk. Three Omron optical proximity switches were also mounted on the disk. The proximity switches were used for wall detection at a range of 2 inches. A linear encoder and an optical detector were added to the base unit and attached to the navigation section. The linear encoder was mounted at the exact center of the base unit and was used to measure distance traveled. The navigation unit was mounted to the rolling base using standoffs. The navigation section sent spent speed and direciton information to the base unit. The units were tested together and could successfully navigate the floor plan described in the contest rules.
The last stage built was the detection and extinguishing section. The detection was accomplished using two thermopiles mounted on rotating panels. The panels were rotated using 2 stepper motors. This last section used a 87C752 microcontroller to a) control the stepper motors that rotated the thermopiles, b) use the onchip A/D converter to measure voltage generated by the thermopiles, c) send a three bit direction code to the navigation module if a candle were detected, d) turn on a bilge pump if a signal were sent from the navigation controller. The candle was extinguished using water pumped from a bilge pump.