Abstract
This project’s objective was to design an automated electronic clutching and mechanical shifting system for a formula-style car which is a part of the ergonomics and drivetrain sub-systems. The Formula Society of Automotive Engineers (FSAE) at Midwestern State University (MSU) approved this project to be part of the design and manufacturing of their first-generation vehicle. The shifter and clutch designs meet the requirement for the Senior Design project. Past designs by various teams have demonstrated a variety of methods of clutch actuation and gear shifting. A popular design amongst most teams is paddle shifting and direct clutch actuation. The design calls for electric push buttons on the backside of the steering wheel that allows the driver to manipulate the solenoids needed to manually cycle through the gears. The current study proposes a semi-automatic clutching system together with a mechanical gear shifting system.
Initial brainstorming led to the idea to combine the clutch with the gas pedal. The concept is that if the pedal is pushed down to a certain angle it will release the clutch, allowing the gears engagement. Meaning when the pedal is not depressed the clutch remains engaged disconnecting the drivetrain. The proposed clutching system utilizes a rotary position sensor, a servo motor, and a communication system between the two. The major idea is to integrate the sensor on the gas pedal so that it senses the position of the pedal. The output from the sensor is communicated by the use of a logic unit to a servo motor attached to the clutching lever of the engine. As the gas pedal is pressed the sensor sends a signal to the servo motor to actuate the clutch accordingly, removing the need for a separate clutch pedal. The Arduino is utilized to relay the signal from the position sensor to the servo motor. The gear shifting mechanism is mechanically operated using a shifter that is connected to a solid rod that actuates the gear selector on the engine. The rod selected is an all thread rod wrapped in Nylon, and the shifting lever is a simple pivot type. This system is completely designed and is implemented in the SAE vehicle. Successful implementation demonstrated the usefulness of the system over traditional clutching and shifting systems. Two major advantages of this system are the elimination of a clutch pedal and the longevity of the gearbox. The steps included a significant amount of brainstorming and taking some important decisions together with the instructor.
The team also gained significant experience to employ engineering solutions in an organized manner. As per the author’s knowledge, the proposed design is a novel concept for use in FSAE cars. During the process, the students entirely came up with this idea themselves. Successful completion showed that the students learned to innovate new designs and concepts for a part of a formula-type vehicle using the gained engineering knowledge.
