Digital Signal Processing Reference
In-Depth Information
13 FPGA Robotics Projects
13.1 The FPGA-bot Design
The FPGA-bot shown in Figure 13.1 is a low-cost moving robotics platform
designed for use the DE1, DE2, UP3, or UP2 board. The FPGA-bot is designed
to be a small autonomous vehicle that is programmed to move in response to
sensory input. A wide variety of sensors can be easily attached to the FPGA-
bot.
The round platform is cut from plastic and a readily available 7.2V or 8.4V R/C
rechargeable battery pack is used to supply power. Two diametrically opposed
drive motors move the robot. A third inactive castor wheel or skid is used to
provide stability. The robot can move forward, reverse, and rotate in place. Two
relatively inexpensive radio control servos are used as drive motors. The FPGA
is programmed to act as the controller. The R/C servos are modified to act as
drive motors. The servos are controlled by timing pulses produced by the FPGA
board.
Figure 13.1
The FPGA-bot uses an R/C car battery and R/C servos for drive motors.
13.2 FPGA-bot Servo Drive Motors
A typical radio control servo is shown in Figure 13.2. Servos have a drive
wheel that is controlled by a coded signal. The servo shown is a Futaba S3003
which is identical, internally, to the Tower TS53J servo. Radio control
servomotors are mass-produced for the hobby market and are therefore
relatively inexpensive and consistently available. They are ideally suited for
robotics applications. Internally, the servo contains a DC drive motor (seen on
