Mechanical Engineering Department
BS in Mechanical Engineering
The Formula Hybrid senior project group was tasked with designing and building a drivetrain system for the Cal Poly Society of Automotive Engineers (SAE) Formula Hybrid (FHSAE) team. FHSAE gave customer requirements for performance and geometry for the drivetrain and the FHSAE rulebook has guidelines regarding safety requirements. The team chose to compete in the electric category of the 2012 FHSAE competition. After getting feedback from previous car performance and researching different powertrain options, the senior project team arrived at three conceptual ideas. Using a quality function deployment method, the senior project team chose the concept where two motors independently delivered power to the rear wheels through a chain and sprocket system. Additionally, an electronic control system would handle power delivery to each of the motors to insure proper vehicle operation. The main components of the final drivetrain design consists of: two DC electric motors, two chain/sprocket systems, two motor supports, two gear sprocket/brake rotor mounts, two axle stubs, one axle stubs central support, four constant velocity joints (CVJ’s), two half shafts, and bearings. The main components of the final drivetrain controls and data acquisition design consists of: 1 real-time controller with digital and analog inputs/outputs, and 2 motor controllers. Additionally, a 3-axis accelerometer, a 3 axis-gyroscope, a steering wheel position sensor, and four wheel speed sensors were purchased with the intentions to implement a traction control and torque vectoring control system. The control algorithms were developed, but motor controller issues prevented actual implementation of these advanced control systems. The culmination of the physical drivetrain components and the control and data components will provide the FHSAE team with a car that met their performance requirements while leaving growth opportunities to implement and expand upon the control algorithms developed.