Team 6

Milestone II

Line Following

Electrical

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Figure 1: Electrical configuration of Bender for Milestone 2

Used Port D for Phase, freeing two OC1/OC2

Sensor Diagram

Redesigning The Body

• Attempted to reduce body size by mounting to smaller metal plate.

• Plate required machining or wooden mockup to mount 68HC11, motor control unit and sensors.

Tank Body

• Chris had used dozer style robots for his thesis

• Suggested that treads may make further milestones easier

Tank Body

• This is the assembled tank unit we tried to modify as a base for Bender. (Though colors differ, toy is the same)

• Costs $99.99 plus tax in stores / online (only suckers pay this much).

• SKU 601-8262

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Side-track• To obtain toys cheaply, call around to Radio

Shack stores• Ask for “broken” RC toys (RC toys without

remote control count as broken)• Buy the toy as a part (the tank came down from

$99.99 to $5)• Different Radio Shacks have different prices on

parts; Edmonton Center Radio Shack has best prices so far.

• If they don’t have something immediately, don’t give up. They do a stock cleanup every month, and mark new things as broken.

Tank Body Modification• Removed the missile

launcher, existing PCB, speakers, etc.

• Mounted the 68HC11 on the back of the casing.

• Mounted the sensor housing on the front of the casing.

Sensor Mounts

68HC11 Mount

Problems With Tank

• Too Stable– Leaving one actuator stopped or moving very

slowly with the other at full speed resulted in traveling in a straight line.

– Reversing one actuator and moving the other forward resulted in no forward movement. “Twitchy” behavior exhibited, and unable to progress towards goal while following line.

Solutions…?

• Forced to remount 68HC11 on wooden body due to problems with tank body.

• The sensor housing needed to be drilled again to account for the new body height, but as it was the night before the milestone, Chris was not available

• Used brackets and washers to get housing as close to the appropriate height as possible.