The Vehicle

Team Cornell’s selection of the 2007 Chevy Tahoe and its subsequent conversion for autonomous operation were driven by two primary design requirements: responsiveness and reliability. The system must be quick to respond, without additional time delays and sluggishness beyond even a human’s reflexes. The platform must be reliable because the DUC development cycle is too short to tolerate considerable down-time for vehicle repairs. Team Cornell addressed these two primary requirements with a design consisting of four components: the vehicle chassis, the power subsystem, the actuation, and packaging.

The most significant decision affecting Team Cornell’s development cycle was the choice to design and build the actuation scheme in house, for converting the Tahoe to drive-by-wire operation. This decision was made after an extensive review of performance specifications, costs, and features of commercially available solutions. Team Cornell’s relationship with Moog Aerospace allowed the team to obtain actuators at no cost, and the knowledge and feasibility of repairing an in house system far outweighed the time spent designing the system. Once Team Cornell decided to develop the vehicle actuation in house, a set of design specifications was created based on an analysis of the most demanding maneuvers the Tahoe might experience during the DUC. As a result of this actuation design, the evasive capabilities of the Tahoe are limited only by the Tahoe itself, not by the physical limitations of its actuators.

Each component of the Tahoe – chassis, power, actuation, and packaging – has been implemented in the final competition vehicle, which has logged hundreds of miles of driving.


©2009 Cornell University DARPA Urban Challenge Team