Software

AVI 6.0

The BeagleBoard runs Autonomous Vehicle Intelligence, which we develop in-house. AVI manages the entire sub by reading input from configuration files, sensors, and cameras and sending commands to the motors and lights. It also contains many intelligent algorithms for target location, color identification, and edge detection.

The shift from Windows XP to Angstrom Linux last year required a ground-up rewrite of AVI. So while we called last year’s version AVI 5, it was really a 1.0 release at heart. That’s why, this year, AVI has been evolved and refined to smooth out the kinks and bugs we introduced last year. AVI 6 runs faster, more efficiently, and smarter than its predecessor.

AVNavControl

The feedback control on the dsPIC control board implements a general Proportional-Integral-Derivative control loop, which can be run on any number of feedback inputs. Every feedback mechanism used by the system simply has to supply a configuration, an input value, and a set point. The feedback control process then produces a value from –1 to 1, indicating to the vehicle how it needs to change to reach the set point. The feedback control is used to control not only heading, depth, and pitch, which are handled by the control system PIC, but also for some of the high-level navigation tasks. The control loop itself includes several features, including derivative filtering (important for sensors that have noise spikes occasionally) and mechanisms to help prevent integral windup.