ERO 3.2 Upgrades

The ERO 3.2 upgrades were completed in June, 2007. Replaced foam wheels with "Colson Performa" soft rubber wheels [for better traction] Replaced hard plastic ball casters with soft rubber ball casters [to reduce noise on wood floor] Added full 360° acrylic bumper around 1st floor with 1/8" foam padding [to protect the furniture from ERO, and to protect ERO from the furniture] Added 2 "ribbon switch" sensors behind bumper padding to sense front left or front right collisions Re-located 1st floor control panel to better align under 2nd floor control panel Replaced Electronic Speed Controllers (ESC's) yet again, this time with Victor 884's from IFI Robotics Plotted performance graphs for each of 3 candidate motors and used 2 best matching motors

*** Click on any image to enlarge ***

Drive Train (1st Floor) Updates

Before bumper		Bottom full
Wheel top	"Colson Performa"	Wheel bottom
Tape switches & 18" diameter acrylic bumper	Tape switches installed	Bumper before padding
Complete 1st floor w/ bumper and padding	1st floor back	Victor 884 Electronic Speed Controllers

ERO 3.3 Upgrades

• Added some ESD circuit protection to the Exar UART in an effort to prevent glitches from resetting it all the time
• This was a last-ditch effort to make the Victor 884 speed controllers work. A non-linear-to-linear mapping function was implemented to try to make the speed controllers appear to have a linear response from the point of view of the PID controller.
• The experiment was a failure. In addition to being extremely non-linear, the Victor 884 response was also non-repeatable; so the PID controller could never converge.
• Additionally, the ESD protection attempts on the Exar UART failed

The ERO 3.3 attempts to salvage the Exar UART chip and Electronic Speed Controller were abandoned in March, 2007.

Conclusion: Need [some more] hardware changes (see ERO 3.4)!