State Transition Diagrams of Transient Roll and Pitch

2008-01-2951

12/02/2008

Event
Motorsports Engineering Conference & Exposition
Authors Abstract
Content
In racing, understanding how the setup and setup changes affect the racecar's ability to produce optimum longitudinal and lateral acceleration is vital to producing a winning team. To better understand and characterize how setup and setup changes affect the racecar, the use of state transition diagrams to model the vehicle's transient roll and pitch while negotiating the track is being investigated. State transition diagrams are made up of statistically significant patterns or events, and show the interconnection or transition from one state to another.1 The basic application of a state transition diagram to the phenomena of a racecar's roll and pitch is to identify the locations on the race course of the major events that make up the vehicle braking into, maneuvering through, and accelerating out of a corner. Major events that are examined include the maximum roll and pitch displacements, velocities, and accelerations. These maxima are directly affected by the racecar's roll and pitch stiffness, damping, and polar moments of inertia respectively. Using the Pi Research software, Pi Toolbox, math channels were created to calculate the displacements, velocities, and accelerations from the information collected by the on board data logger. The locations of the maxima were plotted for multiple distinct corners, allowing for visual identification of how a vehicle pitches and rolls while at qualifying and race pace. The results demonstrated clear identifiable locations of roll and pitch maxima for displacement, velocity, and acceleration that were repeated from lap to lap depending on driver input. By comparing the change of the magnitudes and locations of these maxima on a state transition diagram, due to a change in the setup of the racecar, an engineer would have further insight into how actual changes affect the cars roll and pitch characteristics, as well as possible characterization of how the driver prefers the vehicle to maneuver.
Meta TagsDetails
DOI
https://doi.org/10.4271/2008-01-2951
Pages
11
Citation
Dvorak, A., and Fitzhorn, P., "State Transition Diagrams of Transient Roll and Pitch," SAE Technical Paper 2008-01-2951, 2008, https://doi.org/10.4271/2008-01-2951.
Additional Details
Publisher
Published
Dec 2, 2008
Product Code
2008-01-2951
Content Type
Technical Paper
Language
English