| dc.description.abstract | The Texas A&M University Formula SAE program currently has no rigorous method for analyzing
or predicting the overall dynamic behavior of the student-designed racecars. The objective of
this study is to fulfill this need by creating a full vehicle ADAMS/Car model incorporating an
empirical tire-road force model and validating the longitudinal performance of the model by using
vehicle responses recorded at the track. Creating the model requires measuring mass and
inertia properties for each part, measuring the locations of all the kinematic joints, testing the
Risse Racing Jupiter-5 shocks to characterize damping and stiffness, measuring engine torque,
and modeling the tire behavior. Measuring the vehicle performance requires installation of the Pi
Research DataBuddy data acquisition system and appropriate sensors. The 2002 Texas A&M
University Formula SAE racecar, the subject vehicle, was selected because it already included
some accommodations for sensors and is almost identical in layout to the available ADAMS/Car
model Formula SAE templates. The tire-road interface is described by the Pacejka ??94 handling
force model within ADAMS/Car that is based on a set of Goodyear coefficients. The majority of
the error in the model originated from the Goodyear tire model and the 2004 engine torque map.
The testing used Hoosier tires and the 2002 engine intake and exhaust configuration. The
deliverable is a full vehicle model of the 2002 racecar with a 2004 engine torque map and a tire
model correlated to longitudinal performance recorded at the track using the installed data
acquisition system. The results of the correlation process, confirmed by driver impressions and
performance of the 2004 racecar, show that the 2004 engine torque map predicts higher
performance than the measured response with the 2002 engine. The Hoosier tire on the Texas
A&M University Riverside Campus track surface produces 75??3% of peak longitudinal tire
performance predicted by the Goodyear tire model combined with a road surface friction
coefficient of 1.0. The ADAMS/Car model can now support the design process as an analysis
tool for full vehicle dynamics and with continued refinement, will be able to accurately predict
behavior throughout a complete autocross course. | en |
