Synthesize Ideas 1. Software 1.1 PBasic - Basic Stamp I or II Interpreter 1.2 PIC Assembler - 16F84 1.3 Additional Development stations 2. Fire-Fighting Robot See document: Roboprog.mmp (this document) 3. Hardware 3.1 Robot Starter Kits We examined 3 sources of mobile robot "motorized platforms". The Zagros model 99, priced at $230, comes with a 12" round base and no controller. We didn't consider it because it was too large for our application (navigating 18" wide passageways would leave only 3" a side). The Lynxmotion CarpetRover, priced at $115 + $6 cable = $121, comes with a pair of modifiable Hitec HS-300B servos rated each at 42 oz/in torque, 0.19 sec/60 deg speed. It has 3" dia. tires, and a rotating caster on a 6" x 6" durable base. It's maximum speed is 8"/sec., and it comes with a Parallax Basic Stamp I u-controller kit, software, and manual. We liked this base the best but the Stamp I does not have enough speed/memory/IO. We also examined the Parallax Growbot, which is $153 with educational discount. It comes with a pair of modifiable Futaba S-148 servos rated each at 40 oz/in torque, 0.22 sec/60 deg speed, has 2.5" dia wheels, a plastic ball on a piece of buswire for a non-rotateable caster, and uses the Parallax Basic Stamp II controller PC board as a 3.5" x 5.5" base. It comes with the Basic Stamp II controller kit, software and manual. We liked the controller, but the base was too small and flimsy for our application. After reading many web and magazine articles, including Robot Science and Technology premier issue article "Fire Science Meets Robot Technology" by John Piccirillo, we decided to purchase both the Lynxmotion CarpetRover and the Parallax Growbot. We would use both u-controllers, one for sensors and related tasks, the other for motor drive control. Both will mount on the Lynxmotion base. One of the Growbot servos can be used to "radar sweep" a pyro sensor. 3.1.1 Parallax Growbot See document: http://www.parallaxinc.com/stamps/growbot.htm 3.1.2 Lynxmotion CarpetRover Kit See document: http://www.lynxmotion.com/kits.htm 3.2 Add sensors Sensors will be required for navigation and flame detection. 3.2.1 Navigation Navigational Dead Reckoning errors must be overcome with sensors that keep the robot on a correct heading with distance/bearing and wall/object recognition sensory feedback: Infrared Reflective proximity detector See document: http://www.verinet.com/~dlc/projects/botproj.htm Utrasonic proximity detector See document: http://www.zagrosrobotics.com Compass, Dinsmore 1490 See document: http://dinsmoregroup.com/dico/ Wheel encoders Either optical or magnetic wheel encoders will be employed to count off distance traversed. 3.2.2 Flame detection The flame sensor must discern flame from ambient lighting and warm bystanders. Infrared pyrometer This is one possible flame sensor: See document: http://www.acroname.com/robotics/parts/R3-PYRO1.html UV-Tron Ultraviolet flame sensor This is another type of flamesensor: See document: http://www.hpk.co.jp/products/ETD/UVtronE.htm 3.3 Flame extinguisher The flame must be extinguished after the robot is within 12". 3.3.1 solenoid actuated compressed air 3.3.2 fan A homebrew fan consisting of a small high speed 3 VDC motor and a toy airplane propellor was fabricated by Ron Klimas and tested on 2-1-99 in the Lab. It was able to extinguish the flame from 12" away within a few seconds. The motor current however is nearly 3 amps, so a pair of fresh alkaline "D" cell batteries is barely enough to provide 30 seconds of operation. (The battery voltage sagged from 3.2V no-load to 2.3V under load). The battery weight is also a concern. high speed DC motor Radio Shack # 273-223 3 VDC motor, $0.99. toy airplane propellor Amatos Hobby store (New Britain, CT) #712999, $0.89. See next section "Analysis" to follow our design.
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