Following our successful rookie season with the IGVC, PAVE elected to compete in the 17th Annual IGVC, held in June, 2009. Our entry, named Argos, is an all-new robot based loosely upon the design of Kratos, our entry in the 2008 IGVC. This year’s team of student developers consisted of many newly recruited members. Starting in January, 2009, the team fabricated, built, and tested the robot in preparation for the competition.

As the second robot we designed for the IGVC, Argos had the benefit of borrowing from the successes of its predecessor, Kratos, as well as learning from its mistakes. constructing Argos from the ground up, which allowed us to avoid some of the design flaws from our previous entry.

Faculty Adviser: Professor Robert Schapire
Project Manager: Richard Harris
Logistics Coordinator: Alex Tait
Team Members:
Chris Baldassano ’09, Gordon Franken ’09, Will Hu ’09, Jonathan Mayer ’09, Tom Yeung ’09, Richard Harris ’10, Derrick Yu ’10, Michael Fortner ’11, Solomon Abiola ’12, Barbara Hendrick ’12, Joshua Newman ’12, Brenton Partridge ’12, Eric Starr ’12, Alex Tait ’12

 

Chassis and Drivetrain

Unlike Kratos, the chassis of Argos was designed with exterior paneling in mind. The flat sides free from protruding aluminum brackets allowed the exterior panels to fit tightly to the frame. In addition, Argos is equipped with ventilation ports and exhaust fans to prevent overheating. Though much of the raw material for the frame was recycled from Kratos, the design is brand new. Argos is more compact and maneuverable than its predecessor; in fact, at 31 in wide, Argos fits through a standard doorway. A new bi-level layout allows components to be located closer to the drive wheels, giving it a lower moment of inertia, while its taller sensor tower affords a better view of lanes and obstacles.

Argos boasts a new set of motors, powered by a 24-volt electrical system, that enable it to accelerate faster Kratos, and travel at the maximum allowed velocity for the competition. To prevent wheel slippage, its tires were upgraded to a knobbier tread, allowing for a better grip on the grass.

Sensors and Electronics

While Argos uses the same state sensors (GPS, compass, and wheel encoders) as its predecessor, it also incorporates a Gladiator G50 MEMS gyroscope, which directly measure the instantaneous yaw rate, in order to correct for wheel slip. A LabJack data acquisition unit handles all digital I/O operations. Two Victor 885 motor controllers drive the robot’s motors. Argos also features a redesigned emergency stop system, using a 2.4 GHz spread-spectrum wireless radio, which generates and encounters less interference than the 75 MHz analog radio used by Kratos. Relays plug directly into the R/C radio channels and control the continuity of the signal between the LabJack and the motor controllers

Electronics and Computer Hardware

The new 24-volt electrical system is supplied by six 12-volt batteries in a series-parallel configuration and a 24-volt charger. The configuration allows a maximum continuous runtime of 45 minutes at full power. Argos has a single computer, built with off-the-shelf components. An Intel quad-core processor paired with 6 GB of DDR3 RAM are sufficient to handle all of the computing tasks. Two 802.11g wireless routers provide Internet access to the onboard computer and allow it to be accessed remotely.

Software

Achievements of the 2009 IGVC team

Argos placed 1st in the competition’s navigation challenge. Our 2009 technical paper is available as a pdf download.