First Place Tidewater Community College Virginia Beach, VA

2000 ASEE Model Design Competition St. Louis, MO June 19, 2000

TCC's entered two cars into the competition. Car A - This was TCC's main car and demanded most of their efforts.  Rather than following the line, it was pre-programmed to make turns after certain numbers of wheel revolutions.  The car used an infrared sensor to make 8 counts per wheel revolution by focusing it on a black and white pattern of pie slices.  The counts drove three decade counters (capable of counts up to 999).  At precise counts, which could be changed through programming, a programmable logic device (PLD) sent out signals LEFT and STRAIGHT to 555 timers which controlled the steering servo, and STOP which used a 5V relay to disconned the motor.  The car even featured three seven segment displays so that the count could be monitored for troubleshooting.  This was a well-designed car and was extremely reliable.  It finished the course in good time with apparent ease.  (See video on previous page.) Car B - This car used a strategy much like TCC's 1999 car, though the body was very different.  It used two optical sensors to sense the line position.  The sensor voltage was used to vary the resistance in a 555 timer circuit (by using a JFET as a VVR).  As the resistance of the JFET changed, the pulsewidth of the output of the 555 timer changed, and the servo turned.  The circuit was difficult to adjust and the car wasn't as reliable as the team would have liked, though it was able to finish the course most of the time.  Unfortunately, it was unable to finish during the competition. (See video on previous page.)

Team A Members: Robyn Walker (captain), Dave Gary, Norm Doyle, Scott Smith, Tony Brigantic

Team B Members: Robyn Walker (captain), Dave Gary, Norm Doyle, Scott Smith, Tony Brigantic

Faculty Advisors: Paul E. Gordy, PE (PGordy@tcc.edu) Steve M. Ezzell, PE (SEzzell@tcc.edu)

Robyn Walker accepts the 1st Place Award	Norm Doyle accepts the 3rd Place Award	Dave Gary prepares to start Team A's car.
Car A during the practice session.	Team A's approaches the finish line.	Robyn Walker gives Team A's presentation.
Car A	Scott Smith holding Car A	Early body design
Norm prepares to start car A in Charlotte.	Car B follows the line on the track.	Car B - Left Side View
Car B - Front view showing the two infrared sensors used to follow the black line on the track.	Car B follows the curve on TCC's home track.	A closeup of Car B on the curve.