Build Your Own Combat Robot

252 Build Your Own Combat Robot
FIGURE 11-7
Semiautonomous
target-trackingsystem
block
diagram.
your opponent, and your robot’s sensors will lock onto the opponent and take
over the driving. You maintain complete control of the weapon and let your robot
push the opponent around the ring, you can have all the fun smashing its opponent
to pieces with its weapon.
This type of a system needs at least two range detectors, such as the Sharp
GP2D05 or the Devantech SRF04. Place both of these in front of your robot with
the detection beams crossing each other. A microcontroller is used to monitor both
sensors and to control the motor controllers. With this sensor configuration, the
logic for driving the robot is relatively simple. If the left sensor detects the opponent,
turn your robot to the right. If the right sensor detects the opponent, turn your robot
to the left. If both sensors detect the opponent or both detectors do not detect the
opponent, drive forward. You manually drive your robot up to your opponent until
it is within your robot’s crossing beams’ reach, and then you can enable the
semiautonomous tracking system and your robot will close in on your opponent on
its own. Figure 11-7 shows a simplified schematic of this type of control system.
As with the semiautonomous weapons system, an active link must exist between
the radio receiver and the semiautonomous target-tracking system’s
microcontroller. If the microcontroller loses contact with the radio receiver, the
semiautonomous target-tracking system must shut down and enable manual control
of the robot.
Semiautonomous Target Tracking with Constant Standoff Distances
The next level of control is to use the range-finding sensors such as the GP2D02,
GP0D12, SRF04, or the Panasonic 6500. With these sensors, the microcontroller
can be programmed to keep your robot a specific distance from your opponent,
say 12 to 18 inches. If the opponent moves away, your robot will close in on it; and