In creating ReWIRED the team sought to improve upon already successful systems from
last year's ReWIRED. This year's significant upgrades include the implementation of an entirely
new software platform and approach, new custom designed motor controllers, and substantial
upgrades to essential sensory components. ReWIRED is built upon a solid chassis which has
served the team well and hence was left unmodified.
The power system was completely redesigned and the old, worn out batteries retired and
replaced with longer lasting batteries to improve ReWIRED’s running time. The most important
changes include adding fault tolerance and moving from asymmetric to symmetric loading of the
two onboard deep-cycle batteries to prevent future damage. Also, battery monitoring has been
included, making battery maintenance more user-friendly.
Within the embedded system, the previous control scheme relied solely on proportional
encoder feedback. This year a more complex proportional-integral (PI) control algorithm was
used, providing smoother and more predicable movements. Furthermore, the new PI control is
quicker to react to changes in desired speed and direction, improving the vehicle’s response time.
ReWIRED's software was completely re-imagined. A brand new framework was chosen
and completely new strategies were implemented to handle the competition challenges. The
autonomous strategy became more intelligent with the introduction of a new path finding
navigation algorithm in place of the purely reactive model used last year. A mapping component
aggregates all sensor data to build a persistent grid map of its environment and odometry data
goes through a localization routine to correct for accumulated error. The line detection strategy
was redesigned for better handling of noise. A brand new remote GUI application was
implemented to make development and testing more straight forward.