Novel PID Controlled Continuosly-Variable-Transmission for the 2017 CPP Baja Vehicle

Video: Shows the 2017 Cal Poly Pomona vehicle at the 2017 Kansas Baja SAE competition's suspension and traction event. Our team placed 10th for this event among 100 other universities.

Baja SAE is a collegiate design series sponsored by the Society of Automotive Engineers. Every year teams from across the globe design and manufacture one person off-road vehicles and compete in three competitions held across the United States. These four day competitions consist of Static and Dynamic events. The static events consist of a design presentation and sales presentation. The dynamic events are acceleration, suspension and traction, maneuverability and either sled pull or hill climb. Each competition ends with a four-hour endurance race where all student teams are pitted against each other on a track of one mile or greater. The dynamic events test each car's performance as well as its durability.

To maintain fairness and safety, all vehicles must conform to rules published yearly by the Baja SAE coordinators. The most notable rule in the competition is the requirement to use a 10 horsepower Briggs & Stratton engine of the same model called out and it cannot be altered in any way.

“B2.5 Engine Requirement and Restrictions [2017]

To provide a uniform basis for the performance events, all vehicles must use the same engine: a stock four cycle, air cooled, Briggs & Stratton OHV Intek Model 19.

The only engine model accepted at all 2017 Baja SAE North American competitions is Briggs & Stratton model number: 19L232-0054-G1

No other engine models will be accepted. No engine models from previous competition years will be accepted.”

The need to perform in various situational events with limited power from the engine is why the continuously variable transmission (CVT) plays such a crucial role. Based on the limits of all mechanical systems CVT systems, it made more sense to implement an electronically actuated system. At its best, a mechanical system could not be dynamically changed for various scenarios. Additionally, greater integration of systems could be established for future teams.

Working with Kasra Hashemi, we designed, prototyped, tested/validated the electronically controlled CVT (E-CVT) for all 2017 Baja SAE competitions. Additionally, this project E-CVT project was submitted for our Bachelor thesis.

Competition Result Highlights:

  • California 2017
    • 12th Overall
    • 5th in Design
    • 10th in Maneuvarability
    • 13th in Endurance
  • Kansas 2017
    • 4th Overall
    • 4th in Suspension
    • 14th in Sled Pull
    • 8th in Maneuvarability
    • 4th in Design
  • Illinois 2017
    • 3rd in Design
    • 11th in Maneuverability

Acknowledgements:

Mechanical design was accomplished thanks to Kasra Hashemi.

Additionally, this project would not have been possible without the amazing team that was the 2017 Cal Poly Pomona, Baja SAE team and the SAE projects team supervisor Clifford Stover (PE).