Methodology of TekBot Development

To read the color of an object, a simple analog circuit was developed that produces a voltage proportional to the intensity of light reflected from a surface. This output voltage is processed by the TekBot’s microcontroller through the on-board Analog to Digital converter. The source of the reflected light comes from 3 individual LEDs: red, blue and green. The readings taken from each source are then used to determine the surface color. The flexible solution provides recognition of a broad system spectrum of colors and shades, even though the system specification required only recognition of orange, black, blue and white.

The ball capture subsystem was developed using two servos controlling gate arms that enclose a ball and allow the TekBot and ball to roll together, maneuvering as necessary around the arena.

Preliminary design of these sensors and actuators included development of VHDL-AMS models. System Vision was used to verify that these subsystems would work correctly in the context of the full system. This step involved creating schematics that included the individual sensor or actuator subsystem and the necessary power, stimulus, and loads for various test conditions.

These schematic test-benches were then tested, via System Vision simulation, to observe the circuit’s behavior. The waveforms obtained by simulation provided the required visibility into both the models and the subsystem design – any deficiencies were corrected and verified through simulation.