This prototype Four-Wheel Steering system is designed for a Formula SAE racecar. Multiple steering geometries can be applied to optimize the handling across a range of speeds. Ackermann steering geometry at low speeds improves the car’s agility in tight, technical race courses. At high speeds the steering transitions to parallel steering geometry, improving stability and giving the driver more precise control over the vehicle. The system fits seamlessly within the rear suspension packaging of the existing WashU Racing vehicle design and minimizes addition of weight by using compact and lightweight electronic linear actuators to steer the rear wheels. In testing of the system on the WashU Racing racecar, a successful prototype was rendered. It was found in order to eliminate error in the actuator movement, a more developed control system is needed to be designed. Testing of the turning radii for standard steering, low speed Ackerman, and high speed in-concert steering yielded successful results. For a left-handed turn, standard steering resulted in a 20’ radius, the low speed Ackerman resulted in a 15’ radius, and the high speed in-concert resulted in a 24’ radius. Overall, the successful prototype gives hope for the system to be fully implemented within the next couple of years. Full testing of the system can be completed once a safer, and more accurate control system is implemented.
Mechanical Engineering Design Project (MEMS 411)
Wisniewski, Theodore; Sparrow, Andrew; and Rowsell, Phil, "Four-Wheel Steering" (2016). Mechanical Engineering Design Project Class. 49.