The traction control system of the 2011 cooper union FSAE vehicle

A critical limitation preventing newer FSAE teams from improving in the international rankings is that of the person-machine interface, where driver inexperience and lack of training lead to loss of traction. The Traction Control System (TCS) described here uses closed-loop control of available engine power via spark retardation. Two distinct, driver-selectable algorithms were developed which govern TCS operation for either 1) launch control for the straight line acceleration event, or 2) full traction control for all other dynamic events. Launch control uses a spark retard rev limit to allow the driver to hold the engine at the ideal RPM for easy rev matching via flat foot shifting. Wheel speeds are simultaneously monitored to achieve ideal tire slip ratios. The full traction control algorithm uses the launch control method as a basis, but also addresses potential need for corner exit oversteer or engine braking. Front and rear accelerometers determine when the car is in an oversteer condition. Dynamometer data have been acquired off a tuned engine to assist in the initial PID gains used on the track. The vehicle was instrumented with 1) wheel encoders and Hall effect sensors at every wheel, 2) potentiometers on the brake, accelerator, and clutch pedals, and 3) two MEMs-based accelerometer chips. These signals were sent to a MicrochipA dsPICA linked to the ECU via CAN. These systems are all detailed along with their functional requirements and engineering specifications; guidelines for their implementation within a CAN-based vehicle network were outlined. The preliminary results presented here are encouraging and illustrate the effectiveness of this system, which is a work in progress. Lessons learned from how this project was integrated within the school curriculum are also presented. © 2011 SAE International.

Duke Scholars

Author George Delagrammatikas Thomas Lord Department of Mechanical Engineering and Materia ...