Abstract: This thesis presents the development of an electric All-Wheel Drive (eAWD) system for series- parallel through-the-road hybrid electric vehicle. Although this system can be implemented on any automobile with a similar architecture, eAWD is developed specifically for the Ohio State University ChallengeX vehicle. The reconfigured Chevrolet Equinox utilizes a 1.9L Diesel engine, 6-speed automatic transmission, and Belted-Alternator Starter (BAS) to power the front wheels while a larger electric machine drives the rear wheels. A 300V NiMH battery pack acts as the energy storage device for the electrical components. Without a drive shaft coupling the front and rear axle, the only connection between the front and rear wheels is the road -- through-the- road. This provides a significant amount of flexibility with regards to propulsion of the vehicle in the most efficient manner. Additionally, such a complex architecture presents a unique problem when considering the implementation of traction control. The stock Equinox uses a viscous coupling to transmit a certain percentage of torque to the rear wheels when traction is compromised. The hybrid Equinox accomplishes this same task electrically. Initially, a model-based design approach is utilized to develop the eAWD algorithm. Based off of simulators previously developed by the author and The Ohio State University ChallengeX team, cX-TRAC incorporates detailed tire dynamics, as well as the dynamics of the powertrain actuators and vehicle. The result is a fairly complete, but complex simulation tool that requires additional refinement for complete functionality in all modes. From the lessons learned while developing cX-TRAC, the eAWD algorithm is written and implemented on the OSU ChallengeX vehicle. A large variety of tests are conducted on the vehicle with eAWD enabled and disabled. These tests take place on a level basalt tile surface, as well as, a 20% grade with basalt and ceramic tile surfaces. A multitude of configurations are considered for the evaluation of eAWD. Vehicle launch using the engine and rear electric machine with the corresponding wheels on the basalt surface and all four wheels on the basalt surface are included in these configurations. Moreover, split-p testing is accomplished on both the level basalt surface and the inclined surface. Comparing the wheel speeds recorded during each of the tests with eAWD active, and inactive, shows the system developed and implemented herein provides a more than suitable replacement for the viscous coupling of the stock vehicle.Abstract: This thesis presents the development of an electric All-Wheel Drive (eAWD) system for series- parallel through-the-road hybrid electric vehicle.
|Title||:||Development and Implementation of an Electric All-wheel Drive (eAWD) System|
|Author||:||Michael Daniel Arnett|